释义 |
cancer
Can·cer C0062100 (kăn′sər)n.1. A constellation in the Northern Hemisphere near Leo and Gemini.2. a. The fourth sign of the zodiac in astrology.b. One who is born under this sign. In all senses also called Crab. [Middle English, from Latin; see canker.]
can·cer C0062100 (kăn′sər)n.1. a. Any of various malignant neoplasms characterized by the proliferation of anaplastic cells that tend to invade surrounding tissue and metastasize to new body sites.b. The pathological condition characterized by such growths.2. A pernicious, spreading evil: A cancer of bigotry spread through the community. [Middle English; see canker.] can′cer·ous (kăn′sər-əs) adj.cancer (ˈkænsə) n1. (Pathology) any type of malignant growth or tumour, caused by abnormal and uncontrolled cell division: it may spread through the lymphatic system or blood stream to other parts of the body2. (Pathology) the condition resulting from this3. an evil influence that spreads dangerously[C14: from Latin: crab, a creeping tumour; related to Greek karkinos crab, Sanskrit karkata] ˈcancerous adj ˈcancerously adv
Cancer (ˈkænsə) n, Latin genitive Cancri (ˈkæŋkriː) 1. (Astronomy) astronomy a small faint zodiacal constellation in the N hemisphere, lying between Gemini and Leo on the ecliptic and containing the star cluster Praesepe2. (Astrology) astrology a. Also called: the Crab the fourth sign of the zodiac, symbol ♋, having a cardinal water classification and ruled by the moon. The sun is in this sign between about June 21 and July 22b. Also called: Moonchild a person born during a period when the sun is in this sign3. (Physical Geography) tropic of Cancer See tropic1adj (Astrology) astrology born under or characteristic of Cancer Also (for senses 2b, 4): Canceriancan•cer (ˈkæn sər) n. gen. Can•cri (ˈkæŋ kri) for 3. 1. a. a malignant and invasive growth or tumor, esp. one originating in epithelium, tending to recur after excision and to metastasize to other sites. b. any disease characterized by such growths. 2. any evil condition or thing that spreads destructively; blight. 3. (cap.) the Crab, a zodiacal constellation between Gemini and Leo. 4. (cap.) a. the fourth sign of the zodiac. b. a person born under this sign, usu. between June 21 and July 22. [1350–1400; Middle English < Latin: literally, crab] can′cered, adj. can′cer•ous, adj. can′cer•ous•ly, adv. can′cer•ous•ness, n. can·cer (kăn′sər)1. A disease in which cells of a body part become abnormal and multiply without limit. Without treatment, the cells of some cancers may spread to and damage other tissues of the body.2. A tumor, especially a malignant one.Did You Know? The word cancer refers to any of a number of illnesses caused by abnormal cells that multiply out of control. In some people, exposure to certain viruses, toxic chemicals, or abnormal amounts of radiation can cause changes in the parts of a cell's DNA that normally control and limit cell growth. These portions of DNA, called oncogenes, direct cells to multiply abnormally. Large concentrations of cancer cells may produce lumps of cancerous tissue, called tumors, in a particular area of the body. Sometimes cancer cells break free from one area and travel through the bloodstream or lymph to other parts of the body, causing cancerous cells to grow there. Cancer treatments such as chemotherapy and radiation are designed to kill cancer cells, shrink tumors, and prevent the spread of the disease. With advances in the understanding of how genes work, scientists have begun using gene therapy to correct the faulty DNA that causes cancer cells to grow.
Cancer A constellation in the Northern Hemisphere near Leo and Gemini.CancerSee also disease and illness. adenocelea cystic tumor that may develop in the glands.adenosarcomaa malignant glandular tumor of the soft tissues of the body.astroblastomaa malignant tumor that may invade the brain and spinal cord, especially investing blood vessels.astrocytomaa brain tumor composed of large, star-shaped cells called astrocytes.blastomaa neoplasm arising in the blastema, i.e., tissue from which an organ or part is formed. Also blastocytoma.cancericidalof or pertaining to a chemical or process than can destroy malignant cells.cancerophobiacarcinomophobia.cancroid1. of or pertaining to a lesion that resembles cancer. 2. a malignant skin cancer.carcinectomythe surgical removal of a cancer.carcinogenany natural or artificial substance that can produce or trigger cancer, as arsenic, asbestos, ionizing radiation, ultraviolet rays, x rays, and many derivatives of coal tar. — carcinogenic, adj.carcinoida small, yellow tumor that may develop from argentaffin cells in the gastrointestinal mucosa and spread widely throughout the body.carcinolysisthe destruction of malignant cells, as by an antineoplastic drug.carcinoma1. a malignant tumor that may spread to surrounding tissue and distant areas of the body. 2. any kind of epithelial cancer. — carcinomatous, adj.carcinomatosiscarcinosis.carcinomophobia, carcinomatophobia, carcinophobiaan abnormal fear of cancer. Also called cancerophobia.carcinophiliaan afflnity for cancerous tissue, a property of certain chemical agents. — carcinophilic, adj.carcinosis1. an abnormal condition characterized by the growth of numer-ous carcinomas throughout the body. Also carcinomatosis. 2. the process of development of carcinoma.carcinostaticof or pertaining to the slowing or stopping of the growth of a carcinoma.celiotheliomamesothelioma.cerebromaany abnormal mass of brain tissue, malignant or benign.chemosurgerya therapeutic procedure that uses chemicals to destroy pathogenic tissue, especially skin cancers.chemotherapya procedure that uses radioisotopes of various elements, as iodine, phosphorus, and gold, to treat cancers of the thyroid gland, lungs, and other organs.chloromaa malignant, greenish tumor that invades myeloid tissue and fluoresces red under ultraviolet light.chondrocarcinomaa malignant cartilageous tumor of the epithelium.chondrosarcomaa malignant cartilageous tumor that most frequently invades the long bones, pelvis, and the scapula.chordomaa rare congenital tumor of the brain.chorioblastomachoriocarcinoma.choriocarcinomaa uterine malignancy that may develop shortly after conception, during pregnancy, or after an abortion. Also called chorioblastoma, chorionic epithelioma.comedocarcinomaa malignant tumor of the mammary ducts.cystomaany neoplasm or tumor that contains cysts, especially any such tumor that invades the ovaries.cytotechnologythe study of human cells, especially to detect signs of cancer. — cytotechnologist, n. — cytotechnolqgic, adj.erythroleukemiaa malignancy of the blood characterized by abnormally productive bone marrow and the development of oddly-shaped blood cells.gliomaany of the predominant category of brain tumors composed of cancerous glial cells (a type of nerve cell).hepatomaa malignant tumor of the liver that most commonly occurs in association with hepatitis or cirrhosis,leukemiaa malignancy of blood-producing tissues, characterized by proliferating immature white blood cells and infiltration of the spleen, liver, and other organs. Also leukocythemia. — leukemie, leukemoid, adj.leukocythemialeukemia.liposarcomaa cancerous growth of primitive fat cells. Also called lipoma sarcomatode.lymphomaa growth of lymphoid tissue that is commonly cancerous and typically enlarges the lymph nodes.medulloblastomaa malignant tumor that commonly originates in the cere-bellum.melanomaany malignant growth, especially in the skin, that is composed of melanin-producing cells.mesotheliomaa rare malignant tumor that may invade the linings of the lungs and the abdomen. Also called celiothelioma.metastasisthe spread of malignancies, characterized by the cancerous invasion of the lymphatic system, the blood, and body organs. — metastatic, adj. — metastasize, v.neoplasiathe abnormal proliferation of benign or malignant cells. — neoplastic, adj.neoplasmthe abnormal development of benign or cancerous tissue. — neoplastic, adj.neurinomaa tumor that develops in a neural sheath and that may become malignant.neuroblastomaa highly malignant tumor that may develop from the neural plate in an embryo and spread to the bones, liver, and other organs.neurosarcomaa malignant growth composed of neural, connective, and vascular tissues. Also called malignant neuroma.oncogenesisthe process by which a tumor develops. — oncogenic, adj.oncologythe field of medicine that specializes in the study of tumors.osteoclastomaa giant cell bone tumor that most commonly develops at the end of a long bone.osteosarcomaa malignant bone tumor. Also called osteogenic sarcoma.retinoblastomaa common childhood malignancy of the eye that develops from retinal cells.sarcomaa rare malignant tumor of the soft tissues that commonly develops in the lower extremities.ulocarcinomaa malignancy of the gums.ThesaurusNoun | 1. | cancer - any malignant growth or tumor caused by abnormal and uncontrolled cell division; it may spread to other parts of the body through the lymphatic system or the blood streammalignant neoplastic diseasemalignant neoplasm, malignant tumor, metastatic tumor - a tumor that is malignant and tends to spread to other parts of the bodylymphoma - a neoplasm of lymph tissue that is usually malignant; one of the four major types of cancercarcinoma - any malignant tumor derived from epithelial tissue; one of the four major types of cancercancer of the blood, leucaemia, leukaemia, leukemia - malignant neoplasm of blood-forming tissues; characterized by abnormal proliferation of leukocytes; one of the four major types of cancersarcoma - a usually malignant tumor arising from connective tissue (bone or muscle etc.); one of the four major types of cancer | | 2. | Cancer - (astrology) a person who is born while the sun is in CancerCrabindividual, mortal, person, somebody, someone, soul - a human being; "there was too much for one person to do"astrology, star divination - a pseudoscience claiming divination by the positions of the planets and sun and moon | | 3. | Cancer - a small zodiacal constellation in the northern hemisphere; between Leo and Geminizodiac - a belt-shaped region in the heavens on either side to the ecliptic; divided into 12 constellations or signs for astrological purposes | | 4. | Cancer - the fourth sign of the zodiac; the sun is in this sign from about June 21 to July 22Cancer the Crab, Crab | | 5. | Cancer - type genus of the family Cancridaegenus Cancerarthropod genus - a genus of arthropodsCancridae, family Cancridae - many of the best known edible crabsCancer magister, Dungeness crab - small edible crab of Pacific coast of North AmericaCancer irroratus, rock crab - crab of eastern coast of North AmericaCancer borealis, Jonah crab - large red deep-water crab of the eastern coast of North America |
cancernoun1. growth, tumour, carcinoma (Pathology), malignancy Ninety percent of lung cancers are caused by smoking.2. evil, corruption, rot, sickness, blight, pestilence, canker There's a cancer in the system.Related words prefix carcino- fear carcinophobiaTranslationscancer (ˈkӕnsə) noun1. a diseased growth in the body, often fatal. The cancer has spread to her stomach. 癌 癌2. the (often fatal) condition caused by such diseased growth(s). He is dying of cancer. (常指末期的)癌症病情 癌症ˈcancerous adjective 癌的 癌的IdiomsSeecancer stickSee Cancer
Cancer
Cancer [Lat.,=the crab], in astronomy, constellationconstellation, in common usage, group of stars that appear to form a configuration in the sky; properly speaking, a constellation is a definite region of the sky in which the configuration of stars is contained. ..... Click the link for more information. lying on the eclipticecliptic , the great circle on the celestial sphere that lies in the plane of the earth's orbit (called the plane of the ecliptic). Because of the earth's yearly revolution around the sun, the sun appears to move in an annual journey through the heavens with the ecliptic as its ..... Click the link for more information. (the sun's apparent path through the heavens) between Gemini and Leo; it is a constellation of the zodiaczodiac [Gr. zoion=animal], in astronomy, zone of the sky that includes about 8° on either side of the ecliptic. The apparent paths of the sun, the moon, and the major planets all fall within this zone. ..... Click the link for more information. . It contains the star cluster PraesepePraesepe [Lat.,=manger], open star cluster in the constellation Cancer; cataloged as M44 or NGC 2632. It was first recorded by Hipparchus (c.150 B.C.). The cluster is often called the Beehive because of its shape. It contains several hundred stars, many of which are doubles. ..... Click the link for more information. , but no bright stars. The tropic of Cancer takes its name from this constellation, in which the summer solstice was located about 2,000 years ago. Now, because of the precession of the equinoxesprecession of the equinoxes, westward motion of the equinoxes along the ecliptic. This motion was first noted by Hipparchus c.120 B.C. The precession is due to the gravitational attraction of the moon and sun on the equatorial bulge of the earth, which causes the earth's axis to ..... Click the link for more information. , the summer solstice has moved westward into the constellation Gemini. Cancer reaches its highest point in the evening sky in March.
cancer, in medicine, common term for neoplasms, or tumors, that are malignant. Like benign tumors, malignant tumors do not respond to body mechanisms that limit cell growth. Unlike benign tumors, malignant tumors consist of undifferentiated, or unspecialized, cells that show an atypical cell structure and do not function like the normal cells from the organ from which they derive. Cancer cells, unlike normal cells, lack contact inhibition; cancer cells growing in laboratory tissue culture do not stop growing when they touch each other on a glass or other solid surface but grow in masses several layers deep. Loss of contact inhibition accounts for two other characteristics of cancer cells: invasiveness of surrounding tissues, and metastasis, or spreading via the lymph system or blood to other tissues and organs. Whereas normal cells have a limited lifespan controlled by the telomere gene, which signals the end of the cell line, cancer cells contain telomerase, an enzyme that alters the telomere gene and allows the cell to continue to divide. Cancer tissue, growing without limits, competes with normal tissue for nutrients, eventually killing normal cells by nutritional deprivation. Cancerous tissue can also cause secondary effects, in which the expanding malignant growth puts pressure on surrounding tissue or organs or the cancer cells metastasize and invade other organs. Virtually all organs and tissues are susceptible to cancer. Cancers are usually named for their site of origin. Cancer cells that spread to other organs are similar to those of the original tumor, therefore these secondary (metastatic) cancers are still named for their primary site even though they may have invaded a different organ. For example, lung cancer that has spread to the brain is called metastatic lung cancer, rather than brain cancer. Carcinoma in situ refers to a cancer that has not spread. (See neoplasmneoplasm or tumor, tissue composed of cells that grow in an abnormal way. Normal tissue is growth-limited, i.e., cell reproduction is equal to cell death. Feedback controls limit cell division after a certain number of cells have developed, allowing for tissue repair ..... Click the link for more information. for more on cancer nomenclature.) Cancer is the second leading cause of death in the United States. Lung cancerlung cancer, cancer that originates in the tissues of the lungs. Lung cancer is the leading cause of cancer death in the United States in both men and women. Like other cancers, lung cancer occurs after repeated insults to the genetic material of the cell. ..... Click the link for more information. is the leading cause of cancer death in adults; leukemialeukemia , cancerous disorder of the blood-forming tissues (bone marrow, lymphatics, liver, spleen) characterized by excessive production of immature or mature leukocytes (white blood cells; see blood) and consequently a crowding-out of red blood cells and platelets. ..... Click the link for more information. is the most common cancer in children. Other common types of cancer include breast cancerbreast cancer, cancer that originates in the breast. Breast cancer is the second leading cause of cancer death in women (following lung cancer). Although the vast majority of the cases occur in women, some men also get breast cancer. ..... Click the link for more information. (in women), prostate cancerprostate cancer, cancer originating in the prostate gland. Prostate cancer is one of the most malignancies in men in the United States, second only to skin cancer, and as a cause of cancer death in men is second only to lung cancer. ..... Click the link for more information. (in men), and colon cancercolon cancer, cancer of any part of the colon (often called the large intestine). Colon cancer is the second most common cancer diagnosed in the United States. Epidemiological evidence has shown that a diet high in fat and low in fruits, vegetables, and fiber contributes to the ..... Click the link for more information. (see also Hodgkin's diseaseHodgkin's disease, a type of cancer of the lymphatic system. First identified in 1832 in England by Thomas Hodgkin, it is a type of malignant lymphoma. Incidence peaks in young adults and the elderly. ..... Click the link for more information. ). The incidence of particular cancers varies around the world and sometimes according to ethnic group. For instance, African Americans have comparatively higher cancer rates and cancer mortality rates. It is unclear whether this is due to differences in exposure or to biological susceptibility. The incidence of diagnosed cases of cancer rose steadily in the United States for decades, but since the early 21st cent. it has slowly declined. Causes of Cancer Cancer results from mutations of certain genes that allow the cells to begin their uncontrolled growth. These mutations are either inherited or acquired. Acquired mutations are caused by repeated insults from triggers (e.g., cigarette smoke or ultraviolet rays) referred to as carcinogens. There is usually a latency period of years or decades between exposure to a carcinogen and the appearance of cancer. This, combined with the individual nature of susceptibility to cancer, makes it very difficult to establish a cause for many cancers. The most significant avoidable carcinogens are the chemical components of tobacco smoke (see smokingsmoking, inhalation and exhalation of the fumes of burning tobacco in cigars and cigarettes and pipes. Some persons draw the smoke into their lungs; others do not. Smoking was probably first practiced by the indigenous peoples of the Western Hemisphere. ..... Click the link for more information. ). Dietary components, like excessive consumption of alcohol or of foods high in fat and low in fiber rather than fruits and vegetables that contain antioxidantsantioxidant, substance that prevents or slows the breakdown of another substance by oxygen. Synthetic and natural antioxidants are used to slow the deterioration of gasoline and rubber, and such antioxidants as vitamin C (ascorbic acid), butylated hydroxytoluene (BHT), and ..... Click the link for more information. and necessary micronutrients, have also been linked with various cancers. Some cancers may be triggered by hormone imbalances. For example, some daughters of mothers who had been given DESDES or diethylstilbestrol , synthetic nonsteroid female sex hormone having the same physiological effects as estrogen. In the 1940s and 50s DES was mistakenly believed to reduce the risk of miscarriage and was routinely prescribed for pregnant women believed to be at ..... Click the link for more information. (diethylstilbestrol) during pregnancy to prevent miscarriage developed vaginal adenocarcinomas as young women. Aflatoxins are natural mold byproducts that can cause cancer of the liver. Certain carcinogens present occupational hazards. For example, in the asbestosasbestos, common name for any of a variety of silicate minerals within the amphibole and serpentine groups that are fibrous in structure and more or less resistant to acid and fire. ..... Click the link for more information. industry, workers have a high probability of developing lung and colon cancer or a particularly virulent cancer of the mesothelium (the lining of the chest and abdomen). Benzenebenzene , colorless, flammable, toxic liquid with a pleasant aromatic odor. It boils at 80.1°C; and solidifies at 5.5°C;. Benzene is a hydrocarbon, with formula C6H6. ..... Click the link for more information. and vinyl chloride are other known industrial carcinogens. X rays and radioactive elements are also carcinogenic; the high incidence of leukemia and other cancers in Japanese survivors of the atomic bombing of Hiroshima and Nagasaki and the increased incidence of thyroid cancer after the ChernobylChernobyl , Ukr. Chornobyl, abandoned city, N Ukraine, near the Belarus border, on the Pripyat River. Ten miles (16 km) to the north, in the town of Pripyat, is the Chernobyl nuclear power station, site of the worst nuclear reactor disaster in history. On Apr. ..... Click the link for more information. nuclear disaster give evidence of this. Exposure to the ultraviolet radiation of sunlight is the leading cause of skin cancerskin cancer, malignant tumor of the skin. The most common types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma. Rarer forms include mycosis fungoides (a type of lymphoma) and Kaposi's sarcoma. ..... Click the link for more information. . Many other substances have been identified as carcinogenic to a greater or lesser extent, including chemicals in pesticides that leave residues on foods. The Delaney clause, an amendment (1958) to the U.S. Food, Drug, and Cosmetic Act that prohibits even minuscule amounts of carcinogens in the food supply, has provided the impetus for the investigation of many such chemicals but has also been a source of controversy between industry and environmentalists. In the early 20th cent., the American virologist Peyton RousRous, Francis Peyton, 1879–1970, American pathologist, b. Baltimore, educated at Johns Hopkins (B.A., 1900; M.D., 1905). He taught (1906–8) pathology at the Univ. of Michigan and in 1909 joined the Rockefeller Institute (now Rockefeller Univ.), in New York City. ..... Click the link for more information. showed that certain sarcomas affecting fowl could be transmitted by injection of an agent invisible under the microscope and later indentified as an RNA-containing virus. Other research uncovered oncogenic, or tumor-causing, viruses, first in experimental animals and then in humans. The Epstein-Barr virusEpstein-Barr virus (EBV), herpesvirus that is the major cause of infectious mononucleosis and is associated with a number of cancers, particularly lymphomas in immunosuppressed persons, including persons with AIDS. ..... Click the link for more information. , a member of the herpesvirusherpesvirus, any of the family (Herpesviridae) of common DNA-containing viruses, many of which are associated with human disease. See cytomegalovirus; Epstein-Barr virus; herpes simplex; herpes zoster. ..... Click the link for more information. group, has been linked with a number of human cancers, including the lymphomas that often occur in immunosuppressed people, such as people with AIDSAIDS or acquired immunodeficiency syndrome, fatal disease caused by a rapidly mutating retrovirus that attacks the immune system and leaves the victim vulnerable to infections, malignancies, and neurological disorders. It was first recognized as a disease in 1981. ..... Click the link for more information. . Several human papillomaviruseshuman papillomavirus (HPV), any of a family of more than 100 viruses that cause various growths, including plantar warts and genital warts, a sexually transmitted disease. Genital warts, sometimes called condylomata acuminata, are soft and often occur in clusters. ..... Click the link for more information. (HPV) have also been shown to initiate cancers. For example, some types of HPV cause genital warts known as condylomata acuminata, which can lead to invasive cancer of the cervix, vulva, vagina, or penis, and another human papillomavirus has been associated with some forms of Kaposi's sarcomaKaposi's sarcoma , a usually fatal cancer that was considered rare until its appearance in AIDS patients. First described by an Austro-Hungarian physician, Moritz Kaposi, in 1872, it appears in three forms and is characterized by vascular skin tumors. ..... Click the link for more information. . In addition, hepatitishepatitis , inflammation of the liver. There are many types of hepatitis. Causes include viruses, toxic chemicals, alcohol consumption, parasites and bacteria, and certain drugs. ..... Click the link for more information. B has been shown to increase the risk of liver cancer. Bacteria have also been associated with cancer. For example, the Helicobacter pylori bacterium that causes many ulcers is also associated with an increased risk of stomach cancer. Scientists have identified a few cancers in animals that typically develop as a result of the transmission of cancer cells from one individual to another. Tasmanian facial tumor disease, which afflicts Tasmanian devils, was first identified in the 1990s, and the deadly disease, which has spread rapidly through the Tasmanian devil population, has led to the species being declared endangered. Canine transmissible venereal tumor, which is transmitted between dogs during sex, several forms of cancer that infect bivalves, and a sarcoma that infects laboratory hamsters are other known transmissible cancers. Cancer Susceptibility Risk to humans from carcinogens depends upon the dose and a person's biologic susceptibility. Factors influencing a person's biological susceptibility to cancer include age, sex, immune status, nutritional status, genetics, and ethnicity. Only 5% of all cancers in the United States are thought to be explained by inherited genetic mutations. Known genes associated with hereditary cancer include the aberrant BRCA1 and BRCA2 genes that increase breast cancer risk and the HNPCC gene that is linked with colon cancer. In hereditary forms, it is often the normal gene of the allele that is injured or destroyed, leaving the abnormal inherited gene in control. Nonhereditary cancers sometimes involve the same gene mutations that hereditary forms have. Tumor Development Most bodily insults by carcinogens come to nothing because DNA has built-in repair mechanisms, but repeated insults can eventually result in mutations or altered gene expression in key genes called oncogenes and tumor-suppressor genes. Oncogenes produce growth factors, substances that signal a cell to grow and divide into daughter cells; tumor-suppressor genes (such as the p16, p53, and BRCA1 genes) normally produce a negative growth factor that tells a cell when to stop dividing. The abnormally inactivated tumor-suppressor gene or the abnormally activated oncogene is inherited by each of the cell's daughter cells, and a tumor develops. In many cases tumors remain small and in one place (in situ) for years, but some develop their own blood vessels (a process known as angiogenesis) and begin to grow and spread. Symptoms The classic symptoms of cancer are rapid weight loss; a change in a wart or mole; a sore that does not heal; difficulty swallowing; chronic hoarseness, blood in phlegm, urine, or stool (a consequence of angiogenesis); chronic abdominal pain; a change in size or shape of the testes; a change in bowel habits; a lump in the breast; and unusual vaginal bleeding. Many of these and other symptoms are often nonspecific, e.g., weakness, loss of appetite, and weight loss, and thus are not obvious in the early stages. Sometimes the side effects of tumor growth are more severe than the actual effects of the malignancy; for example, some tumors secrete materials such as serotonin and histamine that can cause drastic vascular changes. Conversely, cancers that destroy tissue may also have serious effects, e.g., malignant destruction of bone tissue may raise the blood level of calcium. Prevention and Detection As more has been learned about cancer, emphasis on prevention and early detection has increased. Cessation of smoking and other tobacco use is the most important controllable means of prevention; smoking causes about 30% of the cancer deaths in the United States. A diet low in fat and high in fiber, including a variety of fruits and vegetables (especially those high in antioxidants), is also recommended. Effective protection against the rays of the sun is recommended to avoid skin cancer. Another preventive approach is vaccination against cancer-causing viruses, such as the hepatitis B virus. Cancers caught early, before metastasis, have the best cure rates. A number of screening tools are now available to allow early detection and treatment. Among these are monthly breast self-examinations and regular mammographymammography, diagnostic procedure that uses low-dose X rays to detect abnormalities in the breasts. Tomosynthesis, also known as 3D mammography, is form of mammography that combines X-ray images taken at multiple angles to produce a single three-dimensional image. ..... Click the link for more information. and Pap testsPap test, Pap smear, or Papanicolaou test , medical procedure used to detect cancer of the uterine cervix (see uterus). A scraping, brushing, or smear, is taken from the surface of the vagina or cervix and is prepared on a slide and stained for ..... Click the link for more information. for women, regular self-examination of the testes for young men, and, for older men, regular examination of the prostate glandprostate gland, gland that is part of the male reproductive system. It is an organ about the size of a chestnut and consists of glandular and muscular tissue. It is situated below the neck of the bladder, encircling the urethra. ..... Click the link for more information. with blood tests for prostate-specific antigen (PSA) tumor marker (a substance in the body that heralds an increased cancer risk). Colonoscopy plus physical examination and laboratory tests for carcinoembryonic antigen (CEA) are recommended for detection of colon cancer. Self-examination of the skin is important for the early detection of skin cancers. Suspicion of a tumor may be confirmed by X-ray study, endoscopy (see endoscopeendoscope, any instrument used to look inside the body. Usually consisting of a fiber-optic tube attached to a viewing device, endoscopes are used to explore and biopsy such areas as the colon and the bronchi of the lungs. ..... Click the link for more information. ), blood tests for various tumor markers, and biopsybiopsy , examination of cells or tissues removed from a living organism. Excised material may be studied in order to diagnose disease or to confirm findings of normality. Preparatory techniques depend on the nature of the tissue and the kind of study intended. ..... Click the link for more information. from which the cells are examined by a pathologist for malignancy. Treatment Developments in the treatment of cancer have led to greatly improved survival and quality of life for cancer patients in the past three decades. Traditionally, cancer has been treated by surgery, chemotherapy, and radiation therapy. In recent years immunotherapy has been added to that list. New drugs and techniques are constantly being researched and developed, such as antiangiogenic agents (e.g., angiostatin and endostatin), genetically engineered monoclonal antibodiesmonoclonal antibody, an antibody that is mass produced in the laboratory from a single clone and that recognizes only one antigen. Monoclonal antibodies are typically made by fusing a normally short-lived, antibody-producing B cell (see immunity) to a fast-growing cell, such as ..... Click the link for more information. , retinoid agents, and therapeutic vaccines (agents that stimulate the immune system to attack cancerous cells). For most kinds of cancer, surgery remains the primary treatment. It is most effective if the cancer is caught while still localized. Some cancers that spread to the lymph system are sometimes treated by extensive surgical removal of tissue, but the trend is toward more conservative procedures (see mastectomymastectomy , surgical removal of breast tissue, usually done as treatment for breast cancer. There are many types of mastectomy. In general, the farther the cancer has spread, the more tissue is taken. ..... Click the link for more information. ). Cryosurgery, the use of extreme cold, and electrodessication, the use of extreme heat, are also being used to kill cancerous tissue and the surrounding blood supply. If the cancer has metastasized, surgery is often replaced by or followed by radiation therapy (which is a localized therapy) and chemotherapy (which is a system-wide therapy). For some cancers, radiation therapy—either from an external beam or from implanted radioactive pellets—is the primary treatment. The usual forms are X rays and gamma rays. Use of radioactive elements specific for particular target organs, such as radioactive iodine specific for the thyroid gland, is effective in treating malignancies of those organs. Cytotoxic chemotherapy is used as a primary treatment for some cancers, such as lymphomas and leukemias or as an addition to surgery or radiation therapy. Cytotoxic drugs (drugs that are toxic to cells) are aimed at rapidly proliferating cells and interfere with nucleic acid and protein synthesis in the cancer cell, but they are often toxic to normal rapidly proliferating cells, such as bone marrow and hair cells. Often a combination of cytotoxic drugs is used. Drugs that reduce side effects may be added to the treatment, such as antinausea agents. Hormonal chemotherapy is based upon the fact that the growth of some malignant tumors (specifically those of the reproductive organs) is influenced by reproductive hormones. Tamoxifentamoxifen , synthetic hormone used in the treatment of breast cancer. Introduced in 1978, tamoxifen is used to prevent recurrences of cancer in women who have already undergone surgery to remove their tumors and to control metastatic breast cancer. ..... Click the link for more information. is a naturally occurring estrogen inhibitor used to prevent breast cancer recurrences. Flutamide is sometimes used in prostate cancer to inhibit androgen uptake. Sex-hormone related drugs such as DESDES or diethylstilbestrol , synthetic nonsteroid female sex hormone having the same physiological effects as estrogen. In the 1940s and 50s DES was mistakenly believed to reduce the risk of miscarriage and was routinely prescribed for pregnant women believed to be at ..... Click the link for more information. and tamoxifen, which may be carcinogenic under some conditions, have proven to be protective under others. More specifically targeted drug therapies have begun to be explored as a better understanding of the molecular biology of individual cancers has been developed. Such drugs are designed to kill only cancer cells while having fewer side effects. Gleevec (STI-571), which is used to treat chronic myelogenous leukemia and some other cancers, inhibits certain kinase receptors that become hyperactive in cancer cells, resulting in the cells' rapid reproduction. Immunotherapy (sometimes called biological therapy) uses substances that help the body mobilize its immune defenses. Some attack the tumor itself, while others bolster the body's ability to withstand conventional chemotherapy treatment. Other new or experimental therapies include drugs that inhibit angiogenesis and photodynamic therapy, in which a patient is given a drug to make the tumor light-sensitive, after which the tumor is exposed to bright laser light. The best choice of treatment will increasingly be influenced by the growing field of molecular pathology, in which characteristics of individual cancers (e.g., virulence or resistance to a particular treatment) can be revealed by analysis of their genetic characteristics rather than by the microscope. Besides treatment of the cancer itself, progress has been made in the management of the chronic pain that often accompanies cancer and in the education of patients and physicians in such techniques as biofeedback, acupuncture, and meditation and the appropriate use of narcotics and other medications. Because of improvements in early detection and treatment, many more people are now living with cancer. Over half of all people with cancer now survive for five or more years. Bibliography See C. N. Coleman, Understanding Cancer (2d ed. 2006); A. H. Ko et al., Everyone's Guide to Cancer Therapy (rev 5th ed. 2008); S. Mukherjee, The Emperor of All Maladies (2010); G. Johnson, The Cancer Chronicles (2013). See also publications of the National Cancer Institute and the American Cancer Society. Cancer (kan -ser) (Crab) An inconspicuous zodiac constellation in the northern hemisphere between Gemini and Leo, its brightest stars being of 3rd and 4th magnitude. There are many double and variable stars, including the multiple star Zeta (ζ) Cancri. The area also contains the open clusters Praesepe and the fainter M67 (NGC 2682) and the strong radio source NGC 2623. Abbrev.: Cnc; genitive form: Cancri; approx. position: RA 9h, dec +20°; area: 506 sq deg. Woodcuts of the zodiacal signs Cancer and Scorpio, from a late fifteenth-century astrological text. Reproduced by permission of Fortean Picture Library. Cancer (religion, spiritualism, and occult)Cancer (Latin for “crab”), the fourth sign of the zodiac, is a cardinal water sign. It is a negative (in the value-neutral sense of being negatively charged), feminine sign ruled by the Moon. Its symbol is the crab, and its glyph is said to represent the two claws of a crab. A moody sign, Cancer is the source of the term “crabby.” Cancer is associated with the breasts and the stomach, and people with a Cancer sun sign are prone to digestion and weight problems. The key phrase for Cancer is I feel. Cancer, like many of the other signs of the zodiac, does not have a developed mythology. During the second labor of Hercules (it might be better termed the second feat or test), while he was struggling against the many-headed hydra, a giant crab bit him on the heel to create a diversion. Hercules, however, crushed it underfoot. This crab, Carcinus (Greek for “crayfish”), was an ally of Hera, queen mother of the gods, who opposed Hercules. The crab was rewarded for sacrificing loyalty when Hera promoted it to distinction as the constellation Cancer. The sign Cancer is often compared with a turtle (the symbol for Cancer in the Babylonian zodiac), and a rich source of symbolic associations for Cancer can be found in the image of the turtle, another shoreline dweller. Cancerians are best known for their attachment to home and, like the turtle, would be happy to carry their house everywhere (if only they could!). Although homebodies, they enjoy travel if they know they have a secure home to which they can always return. Like Carcinus, they are strongly attached to their mother (or to the more nurturing parent) and tend to be nurturing parents themselves. They are highly sensitive individuals who are easily “crushed,” which is why they have developed an emotional “shell” within which they can retreat. They are moodier than any of the other signs of the zodiac, and food represents emotional security to them. Like all water signs, they regard emotions as more real than any other aspect of life. The sign that the Sun was in at birth is usually the single most important influence on a native’s personality. Thus, when people say they are a certain sign, they are almost always referring to their sun sign. There is a wealth of information available on the characteristics of the zodiacal signs—so much that one book would not be able to contain it all. Sun-sign astrology, which is the kind of astrology found in newspaper columns and popular magazines, has the advantage of simplicity. But this simplicity is purchased at the price of ignoring other astrological influences, such as one’s Moon sign, rising sign, etc. These other influences can substantially modify a person’s basic sun sign traits. As a consequence, it is the rare individual who is completely typical of her or his sign. The reader should bear this caveat in mind when perusing the following series of sun sign interpretations. One traditional way in which astrologers condense information is by summarizing sign and planet traits in lists of words and short phrases called keywords or key phrases. The following Cancer key words are drawn from Manly P. Hall’s Astrological Keywords: Emotional key words: “Artistic and dreamy, maternal, kindhearted, romantic, domestic, impressionable, psychic, imaginative, serene, intuitive, restless, despondent, sometimes lazy and self-indulgent.” Mental key words: “Versatile, self-sacrificing, receptive, expresses great veneration for ancestry and precedent, thorough, persevering, cautious, reserved, brooding.” At present, there are various astrology report programs that contain interpretations of each of the 12 sun signs. A selection of these for Sun in Cancer has been excerpted below: Very emotional and sensitive, you have an intuitive understanding of the “vibes” around you. You tend to be quite generous, giving, loving and caring, but only when your own needs for emotional support, love and security have been met. If they are not met, you tend to withdraw into yourself and become very insecure and selfish. Your home and family (especially your mother or the person who played that role for you early on) represent security for you and thus assume a larger-than-life importance. Very sentimental, you have vivid and long-enduring memories of the past. No matter how well adjusted you are, you will always need a secret quiet place of your own in order to feel at peace. Feeding others can give you great pleasure; you would enjoy being part of a large family. (From “Professional Natal Report.” Courtesy of Astrolabe [www.alabe.com].) You have powerful emotional attachments to the past, your family, your childhood, those places you associate with safety and security and your beginnings. Maintaining a connection with your roots and heritage and keeping family bonds strong are very important to you. Loyal, devoted, and sentimental, you tend to cling to whatever is dear to you, be it person, familiar place, or cherished possession. You are sympathetic, nurturing, supportive, and very sensitive to the emotional needs of other people. You like to be needed, to care for others, and you often worry about the people you love. You have a very strong need for a sense of belonging and acceptance, and you center much of your life around your home. You are more concerned about people and their feelings than with power, achievement, or position in society. Kindness, consideration, and tenderness impress you more than any sort of honor the world can bestow. You are primarily emotional and your views are often dominated by your feelings and by your own personal, subjective experiences, rather than reason, logic, or abstract principles. It is difficult for you to judge situations in a fair, objective manner for your personal sympathies and loyalties usually enter in. You take things very personally, and sometimes build a wall around yourself to protect yourself from pain and rejection. You feel rather shy and vulnerable at heart. You also tend to be moody, experiencing frequent emotional ups and downs. You need to have a place and time in your life to withdraw, introspect, dream, and replenish yourself; otherwise you become cranky and unhappy with those around you. You function in an instinctive, nonrational manner and like to immerse yourself in creative activities where you can express your feelings, imagination, and instincts. You often love to cook, since it can be both creative and a way to nurture and nourish others. You also have a great affinity for music, because it evokes and communicates feelings that may be difficult or impossible to put into words. Your compassion, sensitivity, and imagination are your strong points. Your faults include an inability to release the past and go forward, clannishness and prejudice, and a tendency to be self-pitying when you meet hardships in life. (From “Merlin,” by Gina Ronco and Agnes Nightingale. Courtesy of Cosmic Patterns [cosmic.patterns.com].) Opening the inner eye, mapping the topography of consciousness, learning to express compassion—these are Cancer’s evolutionary aims. To assist in that work, Cosmic Intelligence has cranked up the volume on the Crab’s ability to feel. No other sign is so sensitive—nor so vulnerable. A certain amount of self-defense is appropriate here; after all, this world isn’t exactly the Garden of Eden. Trouble is, legitimate self-defense can degenerate into shyness or a fear of making changes. You really do care about the hurts that other beings suffer. That’s good news. You also have an instinctive ability to soothe those hurts, homing in on the source of the pain. More good news. The bad news is that you could choose to remain forever protected within the safe (and invisible!) role of the Healer, the Counselor, or the Wise One. With the Sun in Cancer, you feed your solar vitality by finding a role in the world in which you address the hurt in the lives of other beings. You become a nurturer or a healer of some sort. You also need to make sure that you have enough real intimacy and quiet, private time to “nurture the nurturer”—yourself, in other words. Those methods strengthen your sense of identity. They trigger higher states of awareness in you. If you don’t express your soothing wound-binding instincts, all the glories of the world would leave you feeling like an imposter in your own life. And without quiet time and naked intimate honesty, you’ll quickly burn out on playing the role of everyone’s psychotherapist. Like the crab, you’re a vulnerable creature who’s evolved a shell. That’s fine and necessary. But again like the crab, you must eventually shed your shell and grow a larger, more inclusive one, or you’ll be awfully cramped. (From “The Sky Within,” by Steven Forrest. Courtesy of Matrix Software [thenewage.com] and Steven Forrest [www.stevenforrest.com].) Among its several natal programs, Matrix Software created a unique report based on the published works of the early twentieth-century astrologer Grant Lewi (1901–1952). Lewi’s highly original delineations were recognized as creative and insightful by his contemporaries. One measure of the appeal of his work is that his books Astrology for the Millions and Heaven Knows What are still in print. The following is excerpted from the report program “Heaven Knows What”: We the people of the United States, in order to form a more perfect union, establish justice, insure domestic tranquillity, provide for the common defense, promote the general welfare, and secure the blessings of liberty for ourselves and our posterity, do ordain and establish this Constitution for the United States of America. (Preamble to the Constitution of the United States, which as a nation was born in Cancer, July 4, 1776.) The defensive, protective instincts dominate Cancer, whose life aims primarily at security, material and domestic. Capable of great self-sufficiency, or of being a clinging vine (male or female), the Cancer branch will take the turn as indicated by the roots, which must always be in secure soil. If independence serves security, Cancer will be independent; if security depends on another, Cancer will cling. If security requires taking a chance, Cancer will take a chance—generally, if possible, with someone else’s money, and once he has put his capital or someone else’s into a venture, he watches it like a hawk. His sense of responsibility toward another’s money, security, etc., is as deep as if they were his own; he pays his debts and expects others to do the same. It was Coolidge, Cancer President, whose solution to the war debts was of naive simplicity: “They hired the money, didn’t they?” It is this simple, direct possessiveness toward what rightfully belongs to him that makes Cancer outstandingly successful in business, where he makes his fortune buying and selling, rather than in Wall Street. Cancer will gamble when he has a nest egg, not before, and then as a game rather than as a means of livelihood. With livelihood (security), Cancer takes no chances, either in getting it or keeping it. It is therefore tops as a home-making sign; the maternal-paternal instinct is powerful; and the Cancer, male or female, will go to great lengths to protect, defend and improve his home, mate and children. If Cancer remains unmarried, it is because protectiveness has turned somehow into fear or selfishness; or because he feels that in some way his security is best served alone. Cancer protects himself, as well as his possessions, and may protect himself from the chances of emotional hurt by withdrawing into himself and making his security there, alone. This is a pitiable sight, because Cancer really needs a home and should have children, and few persons give the effect of incompleteness more than the introverted Cancerian who has no one to lavish his protectiveness on but himself. For in its complete development, the Cancer protectiveness becomes encompassing love that fills all its world, and warms and comforts those who are lucky enough to live in the sphere of its radiations. (Courtesy of Matrix Software [thenewage.com].) The following excerpt comes not from a natal report program, but from David Cochrane’s 2002 book, Astrology for the 21st Century. Based on lessons for astrology students, it approaches the signs of the zodiac from a somewhat different perspective than the other short delineations cited here: The strongest attributes of Cancer that I have noticed is very strong attachment to people and things that they are familiar with, and having their feelings hurt by loved ones. Cancer depends on close friends and family for the support and love they give, although they rarely discuss it. These views of Cancer agree closely with the findings of most astrologers. I have also observed that Cancer is easily prone to feelings of jealousy if it feels excluded from the inner circle of closeness, and sometimes is suspicious that it is being pushed away or kept out of something when this is not the case. Cancer is also inclined to be careful about spending money, and is usually aware of the exact balance in the bank account, and sometimes will go to great lengths to ensure prosperity and financial strength; money is security and protects the family, and Cancer tends not to trust the outer world to provide in the future. Cancer’s concern for financial security appears to be a symptom of its tendency to be emotionally attached and bonded to close friends and family, and a fear of losing the closeness from an uncaring outer world. (Courtesy of Cosmic Patterns [cosmic.patterns.com] and David Cochrane [kepler@astrosoftware.com].) A number of specialized report programs have been developed that offer useful supplements to the generic delineations of general reports. The following sun-sign interpretation has been drawn from a program written by Gloria Star (originally part of her book Astrology: Woman to Woman) that generates a specialized report for women: With your Sun in Cancer you can radiate a kind of comfort and care which comes from the core of your being. You thrive most when you’re taking part in nourishing—whether you’re tending your garden, teaching others, safeguarding children or fostering growth in a company. You may express strong sentimentality due to your attachment to the past, and can be especially tenacious with situations, people and your goals. Emotional sensitivity is simply a part of your essence, although your protective shell can fool people. Even when you’re expressing your assertiveness and will, your emotional sensitivity acts as a filter. You innately know that expressing your masculine side has nothing do with acting like a man, but that, instead, you can assert yourself and enjoy the edge that being a woman confers. Your projection of the masculine has a feminine quality—Cancer is a feminine water sign! Before you can readily assert yourself, you must “get a feeling” for the person or situation; it’s almost as though you turn inward before you turn outward. It may be difficult for you to stand up to boisterous, power-hungry individuals, and your shields are likely to go up when you’re confronted with circumstances that seem to assault your vulnerability. However, once you’re more at home with a situation, your sensitivity will help you navigate through it more gracefully than some of those rowdy types of individuals. You appreciate sensitive men, although you may attract men who need to be mothered. As you’ve discovered, there are many ways to nurture …. However, you may also think you need a man to protect you. When you step back and look at it, who is protecting whom? Your drive to accomplish recognition may be stimulated by your need to create the security you need for yourself and your family, and once you have children, they may take first priority. Regardless of your priorities, you will feel successful only when you’ve created a real sense of security with your Sun in Cancer. Defining this security is a very personal thing, and you must be happy with your own definition. Your work, your roles within your family, and your creativity all depend upon your sensitivity in this regard, since when you’re insecure, you hang on tenaciously to everybody and everything. But when you’re feeling stabilized, you don’t even over-water the plants! (From “Woman to Woman,” by Gloria Star. Courtesy of Matrix Software [thenewage.com] and Gloria Star [glostar@aol.com].) Responding to the revival of interest in pre-twentieth-century astrology, J. Lee Lehman developed a report program embodying the interpretive approach of traditional astrology. The following is excerpted from her book Classical Astrology for Modern Living and her computer program “Classical Report”: You are inconstant, easily changing your purpose, and sensitive to changes of Moon phase. You are innocent, cheerful, libidinous, and a lover of recreations like music, dancing, sports and games. If stressed, you suffer from poor digestion, and you have a tendency to edema, or water retention. You are a Water Sign, which means that you are “cold” and “wet.” The “wet” component means, among other things, that you blur distinctions, and that you are more swayed by passion than by intellectual argument. At your worst, you see too many connections, becoming lost in conspiracies. At your best, you spot the connection that everyone else missed. You are perceived as being “cold,” which in your case simply means you may not be quickly reacting on a surface level. In the modern parlance, it fits better with “cold and dry” than with simply “cold.” However, a “cold” type is basically lethargic, or slow to react. Here we have an interesting apparent contradiction: your emotions run deep, but that doesn’t mean you’re talking about them all the time! The quiet quality of “cold” may mislead others about what you’re feeling. The “problem” with “cold” is that it makes it hard for you to forget slights. Because you don’t tend to lash out immediately, it’s hard for you not to allow your anger to build up. The sign of Cancer is called a Cardinal sign in astrology, which means that you are better at starting new things than on finishing them. Laboring overlong at any task is not your strong suit. (Courtesy of J. Lee Lehman, Ph.D., copyright 1998 [www.leelehman.com].) Readers interested in examining interpretations for their Chinese astrological sign should refer to the relevant entry. A guide for determining one’s sign in the Chinese system is provided in the entry on the Chinese zodiac. Sources:Cochrane, David. Astrology for the 21st Century. Gainesville, FL: Cosmic Patterns, 2002.Forrest, Steven. The Inner Sky: How to Make Wiser Choices for a More Fulfilling Life. 4th ed. San Diego: ACS Publications, 1989.Green, Landis Knight. The Astrologer’s Manual: Modern Insights into an Ancient Art. Sebastopol, CA: CRCS Publications, 1975.Hall, Manly P. Astrological Keywords. New York, Philosophical Library, 1958. Reprint, Savage, MD: Littlefield Adams Quality Paperbacks, 1975.Lehman, J. Lee. Classical Astrology for Modern Living: From Ptolemy to Psychology & Back Again. Atglen, PA: Whitford Press, 1996.Lewi, Grant. Astrology for the Millions. 5th rev. ed. St. Paul, MN: Llewellyn, 1978.Lewi, Grant. Heaven Knows What. St. Paul, MN: Llewellyn, 1969.Lewi, Grant. Astrology & Your Child: A Handbook for Parents. St. Paul, MN: Llewellyn, 2001.Star, Gloria. Astrology: Woman to Woman. St. Paul, MN: Llewellyn, 1999.Cancer a zodiacal constellation whose brightest star has a visual stellar magnitude of 3.5. The open cluster M44 (Praesepe), which is visible to the naked eye, is in Cancer. Two thousand years ago, when astronomical terminology was created, the winter solstice occurred in Cancer, as a consequence of which the earth’s northern tropic is still called the Tropic of Cancer. The best conditions for observation occur in January and February. The constellation is visible throughout the USSR.
Cancer (also carcinoma), a malignant tumor of epithelial tissue. The probable origin of the term “cancer” is related to its growth pattern; that is, cancer often grows into surrounding tissue in cords that resemble the claws of a crustacean. This growth is easily observable in, for example, breast or skin cancer. In many countries, for instance, France, “cancer” refers to any malignant tumor, regardless of its tissue origin and structure. A cancerous tumor consists of basic tissue that determines the nature of the tumor (epithelial parenchyma) and connective supporting tissue (stroma) that contains blood and lymph vessels. There are two types of normal epithelium—columnar epithelium and squamous epithelium. On this basis, cylindrical carcinoma (also called glandular cancer or adenocarcinoma) and squamous cell carcinoma are distinguished. Cylindrical carcinoma originates most often in the glandular cells of gastrointestinal mucosa. Squamous cell carcinoma originates in the cover cells of the skin and in the mucosa of the mouth, respiratory tract, and genitourinary tract. A tumor may be dense (scirrhous) or soft (medullary or cerebriform), depending on the degree of the stroma’s development. Sometimes cancer cells partially retain the functions of the original tissue, for example, stomach cancer cells continue to produce mucus during mucinous carcinoma. However, cancer cells are generally atypical, and their shape and size vary considerably. Special functions of the epithelium are lost or distorted. Normal squamous epithelial cells are characterized by cornification. In squamous cell carcinoma, the cornification of epithelial cells is replaced by the formation of peculiar rounded masses of keratic matter that do not have any functional significance. Cancer cells differ from normal cells according to the following characteristics: cytogenetic characteristics (atypical mitosis, disruption of the karyotype), electron-microscopic characteristics (decrease in mitochondria and a simplification of their structure, disorganization of membrane formations), biochemical characteristics (change in the spectrum of enzymes, change in the content and composition of DNA and RNA), and immunological characteristics (the replacement of normal antigens with tumor antigens). The atypia may also affect the stroma of the cancer, which acquires features characteristic of sarcoma; the tumor formed is called carcinosarcoma. Cancer is usually preceded by the pathological processes of precancer. Cancer is characterized by its ability to invade adjacent healthy tissue and destroy it. Blood and lymph vessels are often damaged. Cancer cells are disseminated through the body primarily by the lymph stream, but also by the blood stream. They then settle in various organs and tissues, and, as a result, secondary nodules are formed. Different types of cancer are characterized by metastases to different organs. Lung cancer or cancer of the prostate, mammary, or thyroid glands, for example, often metastasize to the bones. Cancerous tissue may undergo partial necrosis and decomposition. Hemorrhaging and ultimately anemia may result. Necrotic areas may become infected and suppurate. Secondary infections complicate the course of cancer and make diagnosis difficult in the later stages of the disease. In certain parts of the body, cancerous tumors can interfere with vital bodily functions. Cancer of the esophagus, for example, leads to forced starvation, and cancer of the urinary tract to urinary retention. In the late stages of cancer severe emaciation, or cancerous cachexia, sometimes develops. Biopsy, a cytological examination method, and X rays are important in the diagnosis of cancer. L. M. SHABAD What does it mean when you dream about cancer?To dream about cancer does not necessarily mean that the dreamer either has or will contract this disease. Often dreaming of cancer indicates a condition in the dreamer’s life that is hopeless and has been consuming physical or emotional resources for too long. cancer[′kan·sər] (medicine) Any malignant neoplasm, including carcinoma and sarcoma.
Cancer[′kan·sər] (astronomy) A constellation with right ascension 9 hours, declination 20°N. Abbreviated Canc. Also known as Crab. Cancercrab (June 21–July 22). [Astrology: Hall, 314]See: Zodiaccancer any type of malignant growth or tumour, caused by abnormal and uncontrolled cell division: it may spread through the lymphatic system or blood stream to other parts of the body www.jasperweb.com/texascanceronline www.cancercare.org
Cancer1. Astronomy a small faint zodiacal constellation in the N hemisphere, lying between Gemini and Leo on the ecliptic and containing the star cluster Praesepe 2. Astrologya. the fourth sign of the zodiac, symbol ♋, having a cardinal water classification and ruled by the moon. The sun is in this sign between about June 21 and July 22 b. a person born during a period when the sun is in this sign 3. tropic of Cancer See tropic4. Astrology born under or characteristic of Cancer Cancer (dreams)Dreams are symbolic and not literal—most of the time. Cancer tumors in dreams represent a variety of unprocessed psychological and emotional materials that the dreamer may be obsessing on; they represent all of those things that bother, disturb, anger, or hurt us and that we never directly deal with or let go of. The dreamer’s mental, psychic, or emotional problems may be proliferating and infecting many areas of thought and function. You may be experiencing anxiety and fear as a result of a bad habit or a certain situation in your daily life. However, if you are very worried and cannot get it out of your mind, go for a physical. When is the last time you did that anyway? In more superstitious interpretations, dreaming of cancer may be considered a dream of the contrary, but also of warning!cancer
Cancer DefinitionCancer is not just one disease, but a large group of almost 100 diseases. Its two main characteristics are uncontrolled growth of the cells in the human body and the ability of these cells to migrate from the original site and spread to distant sites. If the spread is not controlled, cancer can result in death.DescriptionOne out of every four deaths in the United States is from cancer. It is second only to heart disease as a cause of death in the states. About 1.2 million Americans are diagnosed with cancer annually; more than 500,000 die of cancer annually.Cancer can attack anyone. Since the occurrence of cancer increases as individuals age, most of the cases are seen in adults, middle-aged or older. Sixty percent of all cancers are diagnosed in people who are older than 65 years of age. The most common cancers are skin cancer, lung cancer, colon cancer, breast cancer (in women), and prostate cancer (in men). In addition, cancer of the kidneys, ovaries, uterus, pancreas, bladder, rectum, and blood and lymph node cancer (leukemias and lymphomas) are also included among the 12 major cancers that affect most Americans.Cancer, by definition, is a disease of the genes. A gene is a small part of DNA, which is the master molecule of the cell. Genes make "proteins," which are the ultimate workhorses of the cells. It is these proteins that allow our bodies to carry out all the many processes that permit us to breathe, think, move, etc.Throughout people's lives, the cells in their bodies are growing, dividing, and replacing themselves. Many genes produce proteins that are involved in controlling the processes of cell growth and division. An alteration (mutation) to the DNA molecule can disrupt the genes and produce faulty proteins. This causes the cell to become abnormal and lose its restraints on growth. The abnormal cell begins to divide uncontrollably and eventually forms a new growth known as a "tumor" or neoplasm (medical term for cancer meaning "new growth").In a healthy individual, the immune system can recognize the neoplastic cells and destroy them before they get a chance to divide. However, some mutant cells may escape immune detection and survive to become tumors or cancers.Tumors are of two types, benign or malignant. A benign tumor is not considered cancer. It is slow growing, does not spread or invade surrounding tissue, and once it is removed, doesn't usually recur. A malignant tumor, on the other hand, is cancer. It invades surrounding tissue and spreads to other parts of the body. If the cancer cells have spread to the surrounding tissues, even after the malignant tumor is removed, it generally recurs.A majority of cancers are caused by changes in the cell's DNA because of damage due to the environment. Environmental factors that are responsible for causing the initial mutation in the DNA are called carcinogens, and there are many types.There are some cancers that have a genetic basis. In other words, an individual could inherit faulty DNA from his parents, which could predispose him to getting cancer. While there is scientific evidence that both factors (environmental and genetic) play a role, less than 10% of all cancers are purely hereditary. Cancers that are known to have a hereditary link are breast cancer, colon cancer, ovarian cancer, and uterine cancer. Besides genes, certain physiological traits could be inherited and could contribute to cancers. For example, inheriting fair skin makes a person more likely to develop skin cancer, but only if he or she also has prolonged exposure to intensive sunlight.There are several different types of cancers:- Carcinomas are cancers that arise in the epithelium (the layer of cells covering the body's surface and lining the internal organs and various glands). Ninety percent of human cancers fall into this category. Carcinomas can be subdivided into two types: adenocarcinomas and squamous cell carcinomas. Adenocarcinomas are cancers that develop in an organ or a gland, while squamous cell carcinomas refer to cancers that originate in the skin.
- Melanomas also originate in the skin, usually in the pigment cells (melanocytes).
- Sarcomas are cancers of the supporting tissues of the body, such as bone, muscle and blood vessels.
- Cancers of the blood and lymph glands are called leukemias and lymphomas respectively.
- Gliomas are cancers of the nerve tissue.
Causes and symptomsThe major risk factors for cancer are: tobacco, alcohol, diet, sexual and reproductive behavior, infectious agents, family history, occupation, environment and pollution.According to estimates of the American Cancer Society (ACS), approximately 40% of cancer deaths in 1998 were due to tobacco and excessive alcohol use. An additional one-third of the deaths were related to diet and nutrition. Many of the one million skin cancers diagnosed in 1998 were due to over-exposure to ultraviolet light from the sun's rays.Frequency Of Cancer-Related Death |
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Cancer Site | Number of Deaths Per Year |
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Lung | 160,100 |
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Colon and rectum | 56,500 |
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Breast | 43,900 |
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Prostate | 39,200 |
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Pancreas | 28,900 |
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Lymphoma | 26,300 |
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Leukemia | 21,600 |
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Brain | 17,400 |
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Stomach | 13,700 |
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Liver | 13,000 |
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Esophagus | 11,900 |
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Bladder | 12,500 |
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Kidney | 11,600 |
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Multiple myeloma | 11,300 |
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TobaccoEighty to 90% of lung cancer cases occur in smokers. Smoking has also been shown to be a contributory factor in cancers of upper respiratory tract, esophagus, larynx, bladder, pancreas, and probably liver, stomach, breast, and kidney as well. Recently, scientists have also shown that second-hand smoke (or passive smoking) can increase one's risk of developing cancer.AlcoholExcessive consumption of alcohol is a risk factor in certain cancers, such as liver cancer. Alcohol, in combination with tobacco, significantly increases the chances that an individual will develop mouth, pharynx, larynx, and esophageal cancers.DietThirty-five percent of all cancers are due to dietary causes. Excessive intake of fat leading to obesity has been associated with cancers of the breast, colon, rectum, pancreas, prostate, gall bladder, ovaries, and uterus.Sexual and reproductive behaviorThe human papillomavirus, which is sexually transmitted, has been shown to cause cancer of the cervix. Having too many sex partners and becoming sexually active early has been shown to increase one's chances of contracting this disease. In addition, it has also been shown that women who don't have children or have children late in life have an increased risk for both ovarian and breast cancer.Infectious agentsIn the last 20 years, scientists have obtained evidence to show that approximately 15% of the world's cancer deaths can be traced to viruses, bacteria, or parasites. The most common cancer-causing pathogens and the cancers associated with them are shown in table form.Family historyCertain cancers like breast, colon, ovarian, and uterine cancer recur generation after generation in some families. A few cancers, such as the eye cancer "retinoblastoma," a type of colon cancer, and a type of breast cancer known as "early-onset breast cancer," have been shown to be linked to certain genes that can be tracked within a family. It is therefore possible that inheriting particular genes makes a person susceptible to certain cancers.Occupational hazardsThere is evidence to prove that certain occupational hazards account for 4% of all cancer deaths. For example, asbestos workers have an increased incidence of lung cancer. Similarly, a higher likelihood of getting bladder cancer is associated with dye, rubber and gas workers; skin and lung cancer with smelters, gold miners and arsenic workers; leukemia with glue and varnish workers; liver cancer with PVC manufacturers; and lung, bone and bone marrow cancer with radiologists and uranium miners.EnvironmentRadiation is believed to cause 1-2% of all cancer deaths. Ultra-violet radiation from the sun accounts for a majority of melanoma deaths. Other sources of radiation are x rays, radon gas, and ionizing radiation from nuclear material.PollutionSeveral studies have shown that there is a well-established link between asbestos and cancer. Chlorination of water may account for a small rise in cancer risk. However, the main danger from pollution occurs when dangerous chemicals from the industries escape into the surrounding environment. It has been estimated that 1% of cancer deaths are due to air, land, and water pollution.COMMON PATHOGENS AND THE CANCERS ASSOCIATED WITH THEM |
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Causative Agent | Type of Cancer |
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Viruses | | Papillomaviruses | Cancer of the cervix | Hepatitis B virus | Liver cancer | Hepatitis C virus | Liver cancer | Epstein-Barr virus | Burkitt's lymphoma | Cancers of the upper pharynx | Hodgkin's lymphoma, Non-Hodgkin's lymphoma, Gastric cancers | Human immunodeficiency virus (HIV) | Kaposi's sarcoma Lymphoma | Bacteria | | Helicobacter pylori | Stomach cancer Lymphomas | Cancer is a progressive disease, and goes through several stages. Each stage may produce a number of symptoms. Some symptoms are produced early and may occur due to a tumor that is growing within an organ or a gland. As the tumor grows, it may press on the nearby nerves, organs, and blood vessels. This causes pain and some pressure which may be the earliest warning signs of cancer.Despite the fact that there are several hundred different types of cancers, producing very different symptoms, the ACS has established the following seven symptoms as possible warning signals of cancer:- changes in the size, color, or shape of a wart or a mole
- a sore that does not heal
- persistent cough, hoarseness, or sore throat
- a lump or thickening in the breast or elsewhere
- unusual bleeding or discharge
- chronic indigestion or difficulty in swallowing
- any change in bowel or bladder habits
Many other diseases, besides cancer, could produce the same symptoms. However, it is important to have these symptoms checked, as soon as possible, especially if they linger. The earlier a cancer is diagnosed and treated, the better the chance of it being cured. Many cancers such as breast cancer may not have any early symptoms. Therefore, it is important to undergo routine screening tests such as breast self-exams and mammograms.DiagnosisDiagnosis begins with a thorough physical examination and a complete medical history. The doctor will observe, feel and palpate (apply pressure by touch) different parts of the body in order to identify any variations from the normal size, feel, and texture of the organ or tissue.As part of the physical exam, the doctor will inspect the oral cavity, or the mouth. By focusing a light into the mouth, he will look for abnormalities in color, moisture, surface texture, or presence of any thickening or sore in the lips, tongue, gums, the hard palate on the roof of the mouth, and the throat. To detect thyroid cancer, the doctor will observe the front of the neck for swelling. He may gently manipulate the neck and palpate the front and side surfaces of the thyroid gland (located at the base of the neck) to detect any nodules or tenderness. As part of the physical examination, the doctor will also palpate the lymph nodes in the neck, under the arms and in the groin. Many illnesses and cancers cause a swelling of the lymph nodes.The doctor may conduct a thorough examination of the skin to look for sores that have been present for more than three weeks and that bleed, ooze, or crust; irritated patches that may itch or hurt, and any change in the size of a wart or a mole.Examination of the female pelvis is used to detect cancers of the ovaries, uterus, cervix, and vagina. In the visual examination, the doctor looks for abnormal discharges or the presence of sores. Then, using gloved hands the physician palpates the internal pelvic organs such as the uterus and ovaries to detect any abnormal masses. Breast examination includes visual observation where the doctor looks for any discharge, unevenness, discoloration, or scaling. The doctor palpates both breasts to feel for masses or lumps.For males, inspection of the rectum and the prostate is also included in the physical examination. The doctor inserts a gloved finger into the rectum and rotates it slowly to feel for any growths, tumors, or other abnormalities. The doctor also conducts an examination of the testes, where the doctor observes the genital area and looks for swelling or other abnormalities. The testicles are palpated to identify any lumps, thickening or differences in the size, weight and firmness.If the doctor detects an abnormality on physical examination, or the patient has some symptom that could be indicative of cancer, the doctor may order diagnostic tests.Laboratory studies of sputum (sputum cytology), blood, urine, and stool can detect abnormalities that may indicate cancer. Sputum cytology is a test where the phlegm that is coughed up from the lungs is microscopically examined. It is often used to detect lung cancer. A blood test for cancer is easy to perform, usually inexpensive and risk-free. The blood sample is obtained by a lab technician or a doctor by inserting a needle into a vein and is relatively painless. Blood tests can be either specific or non-specific. Often, in certain cancers, the cancer cells release particular proteins (called tumor markers) and blood tests can be used to detect the presence of these tumor markers. However, with a few exceptions, tumor markers are not used for routine screening of cancers, because several non-cancerous conditions also produce positive results. Blood tests are generally more useful in monitoring the effectiveness of the treatment, or in following the course of the disease and detecting recurrent disease.Imaging tests such as computed tomography scans (CT scans), magnetic resonance imaging (MRI), ultrasound and fiberoptic scope examinations help the doctors determine the location of the tumor even if it is deep within the body. Conventional x rays are often used for initial evaluation, because they are relatively cheap, painless and easily accessible. In order to increase the information obtained from a conventional x ray, air or a dye (such as barium or iodine) may be used as a contrast medium to outline or highlight parts of the body.The most definitive diagnostic test is the biopsy, wherein a piece of tissue is surgically removed for microscope examination. Besides confirming a cancer, the biopsy also provides information about the type of cancer, the stage it has reached, the aggressiveness of the cancer and the extent of its spread. Since a biopsy provides the most accurate analysis, it is considered the gold standard of diagnostic tests.Screening examinations conducted regularly by healthcare professionals can result in the detection of cancers of the breast, colon, rectum, cervix, prostate, testis, tongue, mouth, and skin at early stages, when treatment is more likely to be successful. Some of the routine screening tests recommended by the ACS are sigmoidoscopy (for colorectal cancer), mammography (for breast cancer), pap smear (for cervical cancer), and the PSA test (for prostate cancer). Self-examinations for cancers of the breast, testes, mouth, and skin can also help in detecting the tumors before the symptoms become serious.A recent revolution in molecular biology and cancer genetics has contributed a great deal to the development of several tests designed to assess one's risk of getting cancers. These new techniques include genetic testing, where molecular probes are used to identify mutations in certain genes that have been linked to particular cancers. At present, however, there are a lot of limitations to genetic testing and its utility appears ambiguous, emphasizing the need to develop better strategies for early detection.TreatmentTreatment and prevention of cancers continue to be the focus of a great deal of research. In 2003, research into new cancer therapies included cancertargeting gene therapy, virus therapy, and a drug that stimulated apoptosis, or self-destruction of cancer cells, but not healthy cells. However, all of these new therapies take years of clinical testing and research.The aim of cancer treatment is to remove all or as much of the tumor as possible and to prevent the recurrence or spread of the primary tumor. While devising a treatment plan for cancer, the likelihood of curing the cancer has to be weighed against the side effects of the treatment. If the cancer is very aggressive and a cure is not possible, then the treatment should be aimed at relieving the symptoms and controlling the cancer for as long as possible.Cancer treatment can take many different forms, and it is always tailored to the individual patient. The decision on which type of treatment is the most appropriate depends on the type and location of cancer, the extent to which it has already spread, the patient's age, sex, general health status and personal treatment preferences. The major types of treatment are: surgery, radiation, chemotherapy, immunotherapy, hormone therapy, and bone-marrow transplantation.SurgerySurgery is the removal of a visible tumor and is the most frequently used cancer treatment. It is most effective when a cancer is small and confined to one area of the body.Surgery can be used for many purposes.- Treatment. Treatment of cancer by surgery involves removal of the tumor to cure the disease. This is typically done when the cancer is localized to a discrete area. Along with the cancer, some part of the normal surrounding tissue is also removed to ensure that no cancer cells remain in the area. Since cancer usually spreads via the lymphatic system, adjoining lymph nodes may be examined and sometimes are removed as well.
- Preventive surgery. Preventive or prophylactic surgery involves removal of an abnormal looking area that is likely to become malignant over time. For example, 40% of people with a colon disease known as ulcerative colitis, ultimately die of colon cancer. Rather than live with the fear of developing colon cancer, these people may choose to have their colons removed and reduce the risk significantly.
- Diagnostic purposes. The most definitive tool for diagnosing cancer is a biopsy. Sometimes, a biopsy can be performed by inserting a needle through the skin. However, at other times, the only way to obtain a tissue sample for biopsy is by performing a surgical operation.
- Cytoreductive surgery is a procedure where the doctor removes as much of the cancer as possible, and then treats the remaining area with radiation therapy or chemotherapy or both.
- Palliative surgery is aimed at curing the symptoms, not the cancer. Usually, in such cases, the tumor is so large or has spread so much that removing the entire tumor is not an option. For example, a tumor in the abdomen may be so large that it may press on and block a portion of the intestine, interfering with digestion and causing pain and vomiting. "Debulking surgery" may remove a part of the blockage and relieve the symptoms. In tumors that are dependent on hormones, removal of the organs that secrete the hormones is an option. For example, in prostate cancer, the release of testosterone by the testicles stimulates the growth of cancerous cells. Hence, a man may undergo an "orchiectomy" (removal of testicles) to slow the progress of the disease. Similarly, in a type of aggressive breast cancer, removal of the ovaries (oophorectomy) will stop the synthesis of hormones from the ovaries and slow the progression of the cancer.
Radiation therapyRadiation kills tumor cells. Radiation is used alone in cases where a tumor is unsuitable for surgery. More often, it is used in conjunction with surgery and chemotherapy. Radiation can be either external or internal. In the external form, the radiation is aimed at the tumor from outside the body. In internal radiation (also known as brachytherapy), a radioactive substance in the form of pellets or liquid is placed at the cancerous site by means of a pill, injection or insertion in a sealed container.ChemotherapyChemotherapy is the use of drugs to kill cancer cells. It destroys the hard-to-detect cancer cells that have spread and are circulating in the body. Chemotherapeutic drugs can be taken either orally (by mouth) or intravenously, and may be given alone or in conjunction with surgery, radiation or both.When chemotherapy is used before surgery or radiation, it is known as primary chemotherapy or "neoadjuvant chemotherapy." An advantage of neoadjuvant chemotherapy is that since the cancer cells have not been exposed to anti-cancer drugs, they are especially vulnerable. It can therefore be used effectively to reduce the size of the tumor for surgery or target it for radiation. However, the toxic effects of neoadjuvant chemotherapy are severe. In addition, it may make the body less tolerant to the side effects of other treatments that follow such as radiation therapy. The more common use of chemotherapy is adjuvant therapy, which is given to enhance the effectiveness of other treatments. For example, after surgery, adjuvant chemotherapy is given to destroy any cancerous cells that still remain in the body. In 2003, a new technique was developed to streamline identification of drug compounds that are toxic to cancerous cells but not to healthy cells. The technique identified nine dugs, one of which had never before been identified for use in cancer treatment. Researchers began looking into developing the new drug for possible use.ImmunotherapyImmunotherapy uses the body's own immune system to destroy cancer cells. This form of treatment is being intensively studied in clinical trials and is not yet widely available to most cancer patients. The various immunological agents being tested include substances produced by the body (such as the interferons, interleukins, and growth factors), monoclonal antibodies, and vaccines. Unlike traditional vaccines, cancer vaccines do not prevent cancer. Instead, they are designed to treat people who already have the disease. Cancer vaccines work by boosting the body's immune system and training the immune cells to specifically destroy cancer cells.Hormone therapyHormone therapy is standard treatment for some types of cancers that are hormone-dependent and grow faster in the presence of particular hormones. These include cancer of the prostate, breast, and uterus. Hormone therapy involves blocking the production or action of these hormones. As a result the growth of the tumor slows down and survival may be extended for several months or years.Bone marrow transplantationThe bone marrow is the tissue within the bone cavities that contains blood-forming cells. Healthy bone marrow tissue constantly replenishes the blood supply and is essential to life. Sometimes, the amount of drugs or radiation needed to destroy cancer cells also destroys bone marrow. Replacing the bone marrow with healthy cells counteracts this adverse effect. A bone marrow transplant is the removal of marrow from one person and the transplant of the blood-forming cells either to the same person or to someone else. Bone-marrow transplantation, while not a therapy in itself, is often used to "rescue" patients, by allowing those with cancer to undergo aggressive therapy.Many different specialists generally work together as a team to treat cancer patients. An oncologist is a physician who specializes in cancer care. The oncologist provides chemotherapy, hormone therapy, and any other non-surgical treatment that does not involve radiation. The oncologist often serves as the primary physician and coordinates the patient's treatment plan.The radiation oncologist specializes in using radiation to treat cancer, while the surgical oncologist performs the operations needed to diagnose or treat cancer. Gynecologist-oncologists and pediatric-oncologists, as their titles suggest, are physicians involved with treating women's and children's cancers respectively. Many other specialists also may be involved in the care of a cancer patient. For example, radiologists specialize in the use of x rays, ultrasounds, CT scans, MRI imaging and other techniques that are used to diagnose cancer. Hematologists specialize in disorders of the blood and are consulted in case of blood cancers and bone marrow cancers. The samples that are removed for biopsy are sent to a laboratory, where a pathologist examines them to determine the type of cancer and extent of the disease. Only some of the specialists who are involved with cancer care have been mentioned above. There are many other specialties, and virtually any type of medical or surgical specialist may become involved with care of the cancer patient should it become necessary.Alternative treatmentThere are a multitude of alternative treatments available to help the person with cancer. They can be used in conjunction with, or separate from, surgery, chemotherapy, and radiation therapy. Alternative treatment of cancer is a complicated arena and a trained health practitioner should be consulted.Although the effectiveness of complementary therapies such as acupuncture in alleviating cancer pain has not been clinically proven, many cancer patients find it safe and beneficial. Bodywork therapies such as massage and reflexology ease muscle tension and may alleviate side effects such as nausea and vomiting. Homeopathy and herbal remedies used in Chinese traditional herbal medicine also have been shown to alleviate some of the side effects of radiation and chemotherapy and are being recommended by many doctors.Certain foods including many vegetables, fruits, and grains are believed to offer protection against various cancers. However, isolation of the individual constituent of vegetables and fruits that are anti-cancer agents has proven difficult. In laboratory studies, vitamins such as A, C and E, as well as compounds such as isothiocyanates and dithiolthiones found in broccoli, cauliflower, and cabbage, and beta-carotene found in carrots have been shown to protect against cancer. Studies have shown that eating a diet rich in fiber as found in fruits and vegetables reduces the risk of colon cancer. Exercise and a low fat diet help control weight and reduce the risk of endometrial, breast, and colon cancer.Certain drugs, which are currently being used for treatment, could also be suitable for prevention. For example, the drug tamoxifen (Nolvadex), which has been very effective against breast cancer, is currently being tested by the National Cancer Institute for its ability to prevent cancer. Similarly, retinoids derived from vitamin A are being tested for their ability to slow the progression or prevent head and neck cancers. Certain studies have suggested that cancer incidence is lower in areas where soil and foods are rich in the mineral selenium. More trials are needed to explain these intriguing connections.Prognosis"Lifetime risk" is the term that cancer researchers use to refer to the probability that an individual over the course of a lifetime will develop cancer or die from it. In the United States, men have a one in two lifetime risk of developing cancer, and for women the risk is one in three. Overall, African Americans are more likely to develop cancer than whites. African Americans are also 30% more likely to die of cancer than whites.Most cancers are curable if detected and treated at their early stages. A cancer patient's prognosis is affected by many factors, particularly the type of cancer the patient has, the stage of the cancer, the extent to which it has metastasized and the aggressiveness of the cancer. In addition, the patient's age, general health status and the effectiveness of the treatment being pursued also are important factors.To help predict the future course and outcome of the disease and the likelihood of recovery from the disease, doctors often use statistics. The five-year survival rates are the most common measures used. The number refers to the proportion of people with cancer who are expected to be alive, five years after initial diagnosis, compared with a similar population that is free of cancer. It is important to note that while statistics can give some information about the average survival experience of cancer patients in a given population, it cannot be used to indicate individual prognosis, because no two patients are exactly alike.PreventionAccording to nutritionists and epidemiologists from leading universities in the United States, a person can reduce the chances of getting cancer by following some simple guidelines:- eating plenty of vegetables and fruits
- exercising vigorously for at least 20 minutes every day
- avoiding excessive weight gain
- avoiding tobacco (even second hand smoke)
- decreasing or avoiding consumption of animal fats and red meats
- avoiding excessive amounts of alcohol
- avoiding the midday sun (between 11 A.M. and 3 P.M.) when the sun's rays are the strongest
- avoiding risky sexual practices
- avoiding known carcinogens in the environment or work place
In addition, following the advice of physicians in refraining from certain activities or drugs that are proven as risk factors for certain cancers can help lower one's risk. For instance, while physicians have long known a small increased risk for breast cancer was linked to use of HRT, a landmark study released in 2003 proved the risk was greater than thought. The Women's Health Initiative found that even relatively short-term use of estrogen plus progestin is associated with increased risk of breast cancer, diagnosis at a more advanced stage of the disease, and a higher number of abnormal mammograms. The longer a woman used HRT, the more her risk increased.ResourcesBooksSimone, Joseph V. "Oncology: Introduction." In Cecil Textbook of Medicine, edited by Russel L. Cecil, et al. Philadelphia: W.B. Saunders Company, 2000.Periodicals"HRT Linked to Higher Breast Cancer Risk, Later Diagnosis, Abnormal Mammograms." Women's Health Weekly July 17, 2003: 2."New Way to Stop Cancer Cell Growth Described." Gene Therapy Weekly December 12, 2002: 9."Researchers Find New Way to Trigger Self-Destruction of Certain Cancer Cells." Biotech Week July 16, 2003: 285."Technique Streamlines Search for Anticancer Drugs." Cancer Weekly April 15, 2003: 62."Virus Therapy Attacks Cancer Cells." Cancer Weekly July 29, 2003: 50.OrganizationsAmerican Cancer Society. 1599 Clifton Road, N.E. Atlanta, GA 30329 (800) 227-2345. http://www.cancer.org.Cancer Research Institute (National Headquarters). 681, Fifth Avenue, New York, NY 10022 (800) 992-2623. http://www.cancerresearch.org.National Cancer Institute. 9000 Rockville Pike, Building 31, room 10A16, Bethesda, Maryland, 20892 (800) 422-6237. http://wwwicic.nci.nih.gov.cancer [kan´ser] any malignant, cellular tumor. For specific types, see under the name, such as breast cancer or lung cancer. adj., adj can´cerous. The term cancer encompasses a group of neoplastic diseases in which there is a transformation of normal body cells into malignant ones. This probably involves some change in the genetic material of the cells, deoxyribonucleic acid (DNA). oncogenes are the genes that organisms have evolved to regulate growth and repair of tissues. They are genetic codes for the proteins that function as signals that cells send and receive to regulate proliferation. These oncogenes are the targets of carcinogens. mutation and transformation of oncogenes may permanently affect a cell's ability to control cell growth. Damage to the cell's genetic material may be caused by carcinogenic agents. Normal cell lines can be transformed into cancer cells by viruses, chemical carcinogens, and radiation. Transformed cell lines have the ability to develop into malignant neoplasms. Transformed cells may also be recognized by other characteristics which include altered antigenicity, diminished contact inhibition, reduced requirements for certain nutrients, and the ability to grow in suspension. The altered cells pass on inappropriate genetic information to their offspring and begin to proliferate in an abnormal and destructive way. Normally, cells reproduce regularly to replace worn-out tissues, repair injuries, and allow for growth during the developing years. After these processes have taken place, cellular reproduction stops. Clearly the body in its normal processes regulates cell growth in an orderly manner. In cancer, there is no regulation and cell reproduction and growth is disorderly. The dangers of cancer are related to this chaotic reproduction of malignant cells. As the cancer cells continue to proliferate, the mass of abnormal tissue that they form enlarges, ulcerates, and begins to shed cells that spread the disease locally or to distant sites. This migration is called metastasis. Some cells penetrate neighboring tissues, destroying normal cells and taking their place. Others can enter the blood stream and lymphatic vessels and be carried along in the fluid to another part of the body. Another way malignancy can be spread is by entering a body cavity and coming in contact with a healthy organ; however, this is not common.Causes. It is doubtful that one process is involved in the etiology of all cancers. The exact cause of conversion of normal cells into cancerous ones is still not completely understood. An important factor is permanent alteration in the DNA of the cell, which is passed on to subsequent generations, but we do not know what triggers the change in DNA structure and why some people succumb to a cancer and others do not. Cellular immunity undoubtedly plays some part in one's ability to stop the growth of cancer cells; it is believed by some that most persons develop many small cancers in their lifetime but do not develop clinical signs because their defense mechanisms destroy the malignant cells and prevent their replication. Oncologists recognize that environmental, hereditary, and biological factors all play important roles in the development of cancer (see table). Environmental causes are believed to account for at least 50 per cent and perhaps, in some types, as much as 80 per cent of all cancers. For example, cigarette smoking is directly related to approximately 90 per cent of all cases of lung cancer. Other environmental carcinogens include industrial pollutants and radiation. Among the chemical carcinogens are arsenic from mining and smelting industries; asbestos from insulation, at construction sites and power plants; benzene from oil refineries, solvents, and insecticides; and products from coal combustion in steel and petrochemical industries. Each year new products that in all probability are carcinogenic are being produced by industrial operations. A major concern is the occupational and environmental hazards these chemicals present to those who work in or live near these plants. Radiation from prolonged exposure to the ultraviolet rays of the sun or from injudicious use of diagnostic and therapeutic procedures involving x-rays and radioactive substances is also a significant factor in the incidence of cancer, particularly that of the skin, bone marrow, and thyroid. Hormones, especially the synthetic estrogens given to prevent abortion" >spontaneous abortion, are directly related to some cancers of the female reproductive organs. Viruses as causal agents in the development of cancer have been subjected to intensive research efforts in recent years. The epidemiologic evidence is strongest for a relationship between virus" >hepatitis B virus and carcinoma" >hepatocellular carcinoma and between virus" >human T-lymphotropic virus (HTLV)-1 and T-cell lymphoma. Both have a geographic distribution of cancer prevalence and viral infection as well as case-by-case associations. The association between burkitt's lymphoma and epstein-barr virus (EBV) is likewise strong, except that there seems to be a need for an associated immunodeficiency state, such as that induced by chronic malaria. Similarly, the association between EBV and high-grade lymphoma in Western countries seems to require that an immunodeficiency state be present, either congenital or induced by the human immunodeficiency virus (HIV) or a drug such as cyclosporine. The intriguing fact has been noted that viruses are capable of introducing new genetic material into a normal cell and transforming it into a malignant one, and that cell reproduction may be altered when viruses interact with such carcinogens as chemicals and radiation. Recent studies have shown that an extracellular enzyme, reverse transcriptase, plays an important role in the transmission of genetic information to the cell and thereby facilitates the reproduction of cancer cells. The incidence of cancer in certain populations suggests that other factors are important in its development. It is known, for example, that some families show a high incidence of malignancy among their members, but there is no definite hereditary pattern. There also is a high incidence of cancer in persons receiving drugs for immunosuppression, yet cancer itself is immunosuppressive. It is suggested that prolonged suppression of the body's response" >immune response may eventually impair its ability to distinguish between self and nonself and thus render it unable to destroy malignant cells. When cancer itself acts to suppress the immune response, it may be the result of an overwhelming demand on the body to destroy more foreign cells than it is prepared to cope with at any given time. Aging is another factor to consider in development of malignancy. Although cancer can occur at any age, older persons are more susceptible, perhaps because their powers of adaptability are weakened and they have been exposed to carcinogens longer than have younger persons.Classification. Cancers are classified on the basis of two factors: the type of tissue and the type of cell in which they arise. Using this classification system, it is possible to identify over 150 types of cancer in humans. In the classification of cancers according to the type of tissue from which they evolve, there are two main groups, sarcomas and carcinomas. Sarcomas are of mesenchymal origin and affect such tissues as the bones and muscles; they tend to grow rapidly and to be very destructive. The carcinomas are of epithelial origin and make up the great majority of the glandular cancers and cancers of the breast, stomach, uterus, skin, and tongue. Cell type affects the appearance, rate of growth, and degree of malignancy. Thus, classification of tumors according to the type of cell from which they are derived is important in deciding the course of treatment for a specific malignancy. Staging. An approach to describing and categorizing malignant tumors has been developed by the International Union Against Cancer (UICC) and the American Joint Committee on Cancer (AJCC). It is hoped that by standardizing the classification and staging of tumors, treatment protocols can be established and end results reporting can be utilized to determine the effectiveness of the suggested treatment. Whereas classification of tumors refers to the anatomical and histological descriptions of the tumor (see above), staging refers to the extent of the tumor. The three components of the staging system are the primary tumor (T), regional nodes (N), and metastasis (M). Subscripts may be used to describe the extent to which the malignancy has increased in size, its involvement of regional nodes, and its metastatic development (see table). For example, a tumor may be described as T1N2M0. dukes' classification is a system of staging colorectal tumors, based on the depth of invasion and degree of metastasis. Precancers. Some potentially dangerous cancers appear first in the form of harmless changes in the body's tissues. The danger lies in the fact that such changes have a tendency to become malignant; hence they are known as precancers. Among them are sores that appear as thickened white patches (leukoplakia) in the mouth and on the vulva, some moles, and any chronically irritated area on the skin or the mucous membranes of the mouth and tongue. polyps are also possible precancers.Prevention. Because environmental conditions play an important role in the etiology of many cancers, prevention is aimed at identifying carcinogens, educating the general public about them, and encouraging their avoidance. Equally important, if not more so, is recognition of causative factors related to life style and personal habits. Perhaps the best example of this is the relationship between smoking and lung cancer. When heavy consumption of alcohol is combined with cigarette smoking, the risk for cancer of the larynx, esophagus, and mouth is greatly increased. Nutritional balance is also important in the prevention of cancer. Certain foods and food additives contain specific carcinogenic agents. Nutritional deficiency can lower resistance and increase the risk of certain types of cancers. The decrease in incidence of stomach cancer in most Western countries may possibly be the result of an increase in consumption of fruits and vegetables, since vitamin B12 deficiency (pernicious anemia) is known to be related to increased incidence of stomach cancer. Studies have shown that a relationship exists between obesity and cancer, and between dietary excess, particularly consumption of large amounts of fats, and certain types of cancers. In general, overweight women are at increased risk for cancer of the endometrium, gallbladder, and kidney. Cancers associated with a high dietary intake of fat, with or without obesity, are those affecting the breast, ovary, endometrium, prostate, colon, and pancreas. Although neither saturated nor unsaturated fats are themselves carcinogenic, they act on the endocrine system and affect hormonal activity. The relationship of fat consumption to colon cancer is thought to be due to the effect of bile acids and their metabolites, which have been shown to act as tumor promoters in laboratory animals. In humans, patients with cancer of the colon typically have elevated levels of bile acid metabolites. Studies of various populations throughout the world have shown that bowel cancer is more prevalent among groups who eat large amounts of fat and very little food fiber. Hence the American Cancer Society recommends a low fat, high fiber diet for Americans. The judicious use of hormones for therapeutic purposes also can reduce the incidence of some cancers. The widespread use of diethylstilbestrol (DES) to prevent threatened or habitual abortion and premature labor, beginning in the 1940s, eventually resulted in development of vaginal and cervical cancer in a significant number of the female offspring of women who took the drug while pregnant. As was previously mentioned, estrogens prescribed for relief of menopausal symptoms have been implicated in cancer in women. It is recommended that the lowest possible therapeutic dose be given to relieve the symptoms of menopause and prevent osteoporosis. Cancer of the skin and melanoma" >malignant melanoma are related to prolonged exposure to the ultraviolet radiation in sunlight. The incidence of cancer of the skin is increasing in those persons who value a deep suntan and spend a significant amount of time engaged in outdoor leisure activities. Also at risk are those whose work requires that they be exposed to sunlight for prolonged periods of time, such as farmers. Since most occupational cancers are preventable, increased awareness on the part of industry and the provision of a safe workplace environment can decrease the incidence of many kinds of cancer. It is also necessary for workers to cooperate with management in reducing exposure to carcinogens by complying with rules for preventive measures. Ultimately, the prevention of cancer depends upon knowledge of each person's risk factors for development of cancer, and that person's decision to avoid whenever possible those habits and practices that predispose to the disease. There also should be frequent examination and monitoring of those who are known to be at greater risk.Detection. In addition to routine cancer-related checkups by a health care provider for early detection of cancer, self-examination and awareness of the early danger signs of cancer are suggested as means by which lay persons can participate in detecting it in its earliest stages. Monthly self-examination of the breast is advocated for all adult women, including those who are postmenopausal. Monthly self-examination of the testes is recommended for all males, particularly those in the age group most at risk for testicular cancer, that is, between the ages of 15 and 34 years. Another self-administered screening technique is the test for occult blood, a symptom of colorectal cancer. This requires only that a smear of fecal material be applied to a slide, which is sent to a clinical laboratory for examination. To avoid a false positive reading, the person participating in the test is given instructions regarding ingestion of meat and other foods that could interfere with accurate test findings.Signs of Cancer. There are seven early warning signs of cancer (see table). These signs do not necessarily signify cancer, but should they occur, a health care provider should be consulted and an examination is advisable. Other signs and symptoms depend on location and type of malignancy present.can·cer (CA), (kan'ser), Do not confuse this word with canker or chancre.General term frequently used to indicate any of various types of malignant neoplasms, most of which invade surrounding tissues, may metastasize to several sites, and are likely to recur after attempted removal and to kill the patient unless adequately treated; especially, any such carcinoma or sarcoma, but, in ordinary usage, especially the former. [L. a crab, a cancer] can·cercancerophobia, carcinophobia.cancer (kăn′sər)n.a. Any of various malignant neoplasms characterized by the proliferation of anaplastic cells that tend to invade surrounding tissue and metastasize to new body sites.b. The pathological condition characterized by such growths. can′cer·ous (kăn′sər-əs) adj.cancer An insidious disease which develops from DNA mutations that alter crucial pathways that normally regulate tissue homeostasis, cell survival and/or cell death.cancer Malignancy A malignancy of any embryologic origin, defined by WH Clark, Jr as a '…population of abnormal cells showing temporally unrestricted growth preference (continually increasing number of cells in the population) over normal cells. Such abnormal cells invade surrounding tissues, traverse at least one basement membrane zone, grow in the mesenchyme at the primary site, and may metastasize to distant sites. It is the totality of properties that determines whether a given lesion should be designated as a cancer.' See Actinic cancer, Anal cancer, Apoptosis, Bilateral cancer, Bladder cancer, Bone cancer, Brain cancer, BRCA-related gynecologic cancer, Breast cancer, Burn cancer, Cervical cancer, Chimney sweeps' cancer, Coelomic epithelial cancer, Colorectal cancer, Distant cancer, Early stage breast cancer, Endocrine cancer, Endometrial cancer, Environmental cancer, Epithelial ovarian cancer, Esophagus cancer, Extensive-stage small cell lung cancer, Familial cancer, Gastric cancer, Gynecologic cancer, Head & neck cancer, Hereditary nonpolyposis colorectal cancer, In situ cancer, Infiltrating cancer, Inflammatory breast cancer, Invasive cancer, Interval cancer, Invasive cervical cancer, Islet cell cancer, Kang cancer, Kangri cancer, Khaini cancer, Kidney cancer, Laryngeal cancer, Limited-stage small cell lung cancer, Liver cancer, Localized cancer, Locally advanced cancer, Lung cancer, Major cancer, Meningeal cancer, Microfocal cancer, Minimal breast cancer, Minor cancer, Nonmelanoma cancer, Oral cancer, Nonsmall cell lung cancer, Osteophilic cancer, Ovarian cancer, Pancreatic cancer, Pelvic cancer, Penile cancer, Prostate cancer, Pitch workers' cancer, Radiation-induced cancer, Recurrent cancer, Refractory cancer, Regional cancer, Residual cancer, Scar cancer, Second cancer, Skin cancer, Small cell lung cancer, Solid cancer, Solid cancer, Spontaneous regression of cancer, Terminal cancer, Testicular cancer, Thyroid cancer, Unresectable cancer, Uterine cancer, Vaginal cancer, Virally induced cancer, Yang cancer, Yin cancer, Yin and yang cancer. Cf Carcinoma, Neoplasm, Tumor. can·cer (CA, Ca) (kan'sĕr) General term for malignant neoplasms; carcinoma or sarcoma, especially the former. [L. a crab, a cancer]cancer (kan'ser) [L. cancer, crab, suppurating ulcer] CANCER: (A) Ovarian carcinoma cells and (B) adenocarcinoma of the prostate (orig. mag. ×500)Malignant neoplasia marked by the uncontrolled growth of cells, often with invasion of healthy tissues locally or throughout the body. Cancer is the second leading cause of death in the U.S. after cardiovascular disease. In 2006 the American Cancer Society (ACS) reported that 564,830 Americans died of cancer and that twice that number were newly diagnosed with one form or another of the disease. The most common cancers in the U.S. are lung, breast, colon, prostate, and skin. Because most cancers occur in patients who are 65 or older, the incidence of cancer is expected to increase as the population ages. More than 200 kinds of cancer have been identified. Cancers that arise from epithelial tissues are called carcinomas; from mesenchymal tissues, sarcomas; from glial cells, gliomas; from lymphatic cells, lymphomas; from blood-forming cells, leukemias; from pigmented skin cells, melanomas; from plasma cells, myelomas. Synonym: malignancy (2) See: carcinoma; leukemia; lymphoma; oncogene; sarcomaCancer cells have several reproductive advantages over normal cells. They can make proteins that stimulate their own growth or new blood vessels to bring them nourishment. They can produce enzymes that prevent their chromosomes from aging. They can invade the lymphatic system and bloodstream and find places to grow in new tissues (metastasis). Usually, as cancer cells proliferate, they become increasingly abnormal and require more of the body's metabolic output for their growth and development. Damage caused by their invasion of healthy tissues results in organ malfunction, pain, and, often, death. See: table (Estimated New Cancer Cases and Deaths by Sex, U.S. 2008) EtiologyIonizing radiation, ultraviolet light, some viruses, and drugs that damage nucleic acids may initiate the genetic lesions that result in cancers. The best-known and most widespread type of carcinogen exposure, however, is consumption of tobacco. The ACS estimates that one third of the cancer deaths that occur annually in the U.S. are related to nutrition and other lifestyle factors. Some cancers are familial, i.e., genetic; others result from occupational exposures to carcinogens. Ironically, chemotherapeutic drugs used to treat some cancers may damage chromosomes and occasionally cause secondary malignancies. SymptomsSymptoms of widespread cancer include pain, malnutrition, weakness, fatigue, bone fractures, and strokelike syndromes. Early warning signs of cancer may be remembered by the mnemonic CAUTION: Change in bowel or bladder habit; A sore that does not heal; Unusual bleeding or discharge; Thickening or mass in the breast or other body parts; Indigestion or difficulty in swallowing; Obvious change in a wart or a mole; Nagging cough or hoarseness. People should seek prompt medical attention if they observe any of these signs. DiagnosisThe location of a suspected lesion often dictates the means to diagnose cancer: men with urinary symptoms may be screened for prostate cancer with a prostate specific antigen (PSA) test; an alpha-fetoprotein (AFP) test may be used to screen for liver cancer. Several other tumor markers (such as the CA 125 test for ovarian cancer) are used only after a diagnosis has already been made by other means. Endoscopy and radiography are typically used to locate and assess the extent of the disease, but definitive diagnosis still rests on the examination of cytological specimens (such as the Papanicolaou [Pap] test) or the pathological review of biopsy specimens. See: illustration; table (Controversies in Cancer Screening in the General Population) Screening for cancers can identify some malignancies before they have invaded neighboring tissues or become widespread. The most widely used screening tests include the Pap test for cervical cancer, mammography for breast cancer, prostate specific antigen tests for prostate carcinoma, and occult blood tests and colonoscopy for intestinal cancers. TreatmentSurgery, chemotherapy, immunotherapy, hormone therapy, radiation therapy, and combined-modality therapies often are effective methods for treating patients with cancer. The specific treatment used depends on the type, stage, and location of the cancer and the patient's general health. The pain associated with cancer is often severe. Cancer patients may suffer depression and anxiety and have nutritional deficits. Guidelines addressing these issues are readily available, e.g., from the U.S. Department of Health and Human Services' Agency for Health Care Policy and Research. Publications may be obtained by calling 1-800-4-CANCER or from websites such as from the ACS (www.cancer.org). See: chemotherapy. Patient careThere must be close collaboration among the entire health care team and the patient and family must be encouraged to participate in care . The patient's knowledge of the disease is determined, misinformation corrected, and information supplied about the disease, its progression, its treatment, and expected outcome. Such information should be updated regularly. The patient's and family's coping mechanisms are supported, and verbalization of feelings and fears, esp. with changes in body image, pain and suffering, and dying and death, is encouraged. Participation in local support groups is encouraged for both patients and families. Assistance is provided with personal hygiene and physical care as needed. Physical care is directed at the maintenance of fluid and electrolyte balance and proper nutrition. Nutrition is a special concern because tumors compete with normal tissues for nutrients and grow at their expense and because the disease or treatments can cause anorexia, altered taste sensations, mouth ulcerations, vomiting, diarrhea, and draining fistulas. Nutritional support includes assessing the patient's status and problems, experimenting to find foods that the patient can tolerate, avoiding highly aromatic foods, and offering frequent small meals of high-calorie, high-nutrient soft foods along with fluids to limit fatigue and to encourage overall intake. Intake of noncaffeinated liquids should be encouraged: 2 quarts per day of juices or other caloric beverages in frequent, small amounts rather than water alone. Elimination is maintained by administering stool softeners as necessary if analgesic drugs result in constipation. Using careful and gentle handling, the health care professional assists with range-of-motion exercises, encourages ambulation and mobility, and turns and repositions the immobile patient frequently to decrease the deleterious multisystemic effects of immobilization. The patient is made comfortable by correct body alignment, noninvasive measures (such as guided imagery and cutaneous stimulation), and medication (preferably administered on a regular schedule to prevent pain, with additional dosing to relieve breakthrough pain). Emotional assistance includes allaying the patient's fears of helplessness and loss of control; providing hope for remission or long-term survival but avoiding giving false hope; and providing the patient with realistic reassurance about pain control, comfort, and rest. Psychological counseling and antidepressant therapies may be helpful. Hospice care (at home or in a dedicated center), if needed, is discussed with the patient and family. The goal is to provide good quality of life with minimal discomfort, pain, and restrictions rather than to continue specific therapy. Family members are encouraged to assume an active role in caring for the patient. Communication is fostered between patient and family and other health care providers, and the patient is helped to maintain control and to carry out realistic decisions about issues of life and death. To provide effective emotional support to the patient and family, health care professionals must understand and cope with their own feelings about terminal illness and death and seek assistance with grieving and in developing a personal philosophy about dying and death. They will then be better able to listen sensitively to patients' concerns, to offer genuine understanding and comfort, and to help patients and family work through their grief. bladder cancerA malignancy that arises in the cells of the urinary bladder. In Western nations, most of the cases are transitional cell carcinomas. Common causes include cigarette smoking, occupational exposure to carcinogens, or chronic bladder infection. Symptoms of bladder cancer may include painful urination, bloody urination, or frequent or urgent urination. Depending on the extent of invasion or spread of the tumor, it may be treated with endoscopy, surgery, chemotherapy, or immunotherapy. bone cancerAny malignancy of bone tissue. Primary bone tumors (such as osteosarcomas) are rare in adults; they are seen more often in children and adolescents. Secondary or metastatic bone tumors are far more common. Tumors arising in other areas of the body that metastasize to the bones most often spread from organs such as prostate or breast. breast cancer See: breast cancercervical cancerA malignant neoplasm of the cervix of the uterus. With an incidence of 15:100,000, it is the third most common cancer of the female reproductive tract and causes 5% of all cancer deaths among women. Although it may occur in younger women, the average age at diagnosis is 54. The disease is insidious, asymptomatic in the early stages, and best treated when recognized at an early stage. EtiologySome strains of the human papillomavirus (HPV) are carcinogenic to cervical epithelium. While there are other risk factors (such as tobacco smoking, early age at first intercourse, and having multiple sex partners), HPV is the major factor responsible for the development of this cancer. DiagnosisPeriodic Pap tests are recommended for all sexually active women. The tests identify cellular changes with 95% accuracy. Dilatation and curettage, punch biopsy, and colposcopy may be done if Pap test findings raise the suspicion of cancer. If abnormal cells are detected, HPV testing is often performed to screen for presence of one of the high risk types of the virus. See: Bethesda System, The; cervical intraepithelial neoplasia; colposcopy; cryosurgery; loop electrode excision procedure; Papanicolaou test TreatmentManagement varies from cryotherapy or laser therapy for low-grade squamous intraepithelial lesions, conization for carcinoma in situ, to hysterectomy for preinvasive cervical cancer in women who are not planning to have children. Stage-related management of invasive cervical carcinoma includes radiation and/or hysterectomy. PreventionVaccination against human papillomavirus virus (HPV). See: HPV vaccine. chimney sweeps' cancerCancer of the skin of the scrotum due to chronic irritation by coal soot.colorectal cancer Abbreviation: CRC A malignancy of the colon or rectum. It is the second leading cause of cancer deaths in the U.S. At some time during their lives 6% of Americans will be diagnosed with the disease. In 2008 the ACS estimated that 154,000 Americans would be newly diagnosed with colorectal cancer and that it would cause 50,500 deaths. EtiologyThe cancer occurs more often in people with a family history of the disease, those with familial adenomatous polyposis, and in those with inflammatory bowel diseases such as ulcerative colitis. It also occurs more often in people who are obese than in those who are not and in those who consume a high fat, low-fiber diet. SymptomsSymptoms may be absent or may include change in the usual pattern of bowel habits, esp. in those over 40; recent onset of constipation, diarrhea, or tenesmus in an older patient; bright red or dark blood in the stool. Laboratory findings may include iron-deficiency anemia or positive fecal occult blood tests. DiagnosisDiagnosis may be suggested by findings on digital rectal examination, anoscopy, flexible or rigid sigmoidoscopy, colonoscopy, virtual colonoscopy, or barium enema examination. It is confirmed by biopsy of suspicious lesions. Prevention includes screening of asymptomatic men and women of average risk starting at age 50, annual home fecal occult blood testing (over a three-day period), and colonoscopy every 10 years. During colonoscopy, removal of benign polyps prevents progression to malignant tumors. If polyps are found, colonoscopy should be repeated in 3 to 5 years (depending on the presence of other risk factors). Detection of colorectal cancer at an early stage via colonoscopy offers patients a very high likelihood of cure rate at 5 years. Neither digital rectal examination nor testing of a single stool specimen from the digital exam provides adequate screening. Patients at increased risk for colorectal cancer (those who have had previous colorectal adenomas or resected cancers or a history of ulcerative colitis or of colon cancer in a first-degree relative younger than 60) should undergo screening more frequently and at an earlier age. When colorectal carcinoma is diagnosed, additional tests are conducted to determine the stage of the disease (chest radiographs, CT, MRI, and blood studies, including carcinoembryonic antigen levels, and liver function studies). TreatmentSurgical resection performed by laparotomy, minimally invasive surgery, microsurgery, or laparoscopy can cure localized colorectal cancer. Whatever procedure is used, the type of surgery depends on the location of the tumor, and the goal of the surgery is removal of the malignant tumor and adjacent tissue and any lymph nodes that may contain cancer cells. Adjuvant therapies may include chemoembolization of blood vessels that feed the primary tumor or metastases; radiation therapy; brachytherapy; chemotherapy; or monoclonal antibody therapy. Carcinoembryonic antigen is helpful in monitoring patients during and following treatment to determine effectiveness and detect recurrence or metasasis. Patient careHealth care providers should teach patients the importance of colorectal screening and indicate applicable lifestyle modifications (a low-fat diet, maintenance of a normal body mass index). Patients with familial colon cancer syndromes, such as familial adenomatous polyposis, should be counseled about the need for close surveillance by professional gastroenterologists. Aspirin and other nonsteroidal anti-inflammatory drugs appear to reduce the number of colon polyps, thus decreasing the risk of developing colorectal cancer. Patients interested in such therapy should discuss its potential risks and benefits with their health care providers. Patients diagnosed with colorectal cancer who undergo surgery need counseling about the operation, the duration of recovery, and, in many cases, the use of a postoperative colostomy . Before surgery, a stomal therapist consults with the surgeon regarding appropriate stoma location, and the abdomen is marked. The therapist answers questions from the patient and family and begins to develop a relationship that will support the patient through postoperative care and teaching. Patient and family are encouraged to access the ACS (800-ACS-2345 or www.cancer.org) for additional information. Synonym: carcinoma of the colon; colorectal carcinomaepithelial cancerBasal cell carcinoma.epithelial cancer of the ovary See: ovarian canceresophageal cancer See: esophageal cancerfallopian tube cancerA malignancy that begins to grow in the cells that form the inner surfaces of the fallopian tubes, usually an adenocarcinoma. It is the least common form of gynecological cancer. familial medullary thyroid cancer Abbreviation: FMTC A rare, autosomal, dominantly inherited predisposition to medullary carcinoma of the thyroid. The disease is genetically related to the multiple endocrine neoplasia (MEN) syndromes. However, families affected by FMTC rarely develop hyperparathyroid tumors or pheochromocytoma. gastric cancerAdenocarcinoma of the stomach. About 50% to 60% of all carcinomas of the stomach occur in the pyloric region. About 20% occur along the lesser curvature; the rest are located in the fundus, particularly along the greater curvature. Although this form of cancer is common throughout the world in people of all races, the incidence of gastric cancer exhibits unexplained geographic, cultural, and gender differences, with the highest incidence in men over 40 and higher mortality in China, Korea, Japan, Taiwan, Iceland, Chile, and Austria. From 1930 to the 1990s, the incidence of gastric cancer declined from about 38 cases per 100,000 to about 6 cases per 100,000. In 2010, the ACS estimated there would be 21,000 new cases of gastric cancer in the U.S. and 10,570 deaths from this disease. The prognosis for a particular patient depends on the stage of the disease at the time of diagnosis, but overall the 5-year survival rate is about 19%. Predisposing CausesAlthough the cause of gastric cancer is unknown, predisposing factors include a diet rich in pickled or smoked foods, a history of gastric surgery, and a history of infection by Helicobacter pylori. The disease runs in some families; therefore, there may also be a genetic component. ComplicationsMalnutrition occurs as a result of impaired eating, the metabolic demands of the growing tumor, or obstruction of the GI tract. Iron deficiency anemia results as the tumor causes ulceration and bleeding. The tumor can interfere with the production of the intrinsic factor needed for vitamin B12 absorption, resulting in pernicious anemia. As the cancer spreads to regional lymph nodes and nearby structures and metastasizes to other structures, related complications occur. Signs and SymptomsIn the early stages, the patient may occasionally experience pain in the back or in the epigastric or retrosternal areas that is relieved with nonprescription analgesics. As the tumor grows, the patient may notice a vague feeling of fullness, heaviness, and abdominal distention after meals. Depending on the progression of the cancer, the patient may report weight loss due to disturbance of the appetite; nausea; and vomiting. There may be dysphagia and coffee-ground vomitus if the tumor is located in the cardia and slowly bleeds. Weakness and fatigue are common. Because early symptoms include chronic dyspepsia and epigastric discomfort, patients may self-treat with OTC antacids or histamine blockers, delaying prescribed therapies and allowing the cancer to progress. Palpation of the abdomen may disclose a mass. A skilled examiner may be able to palpate enlarged lymph nodes, esp. in the supraclavicular and axillary regions. Diagnostic StudiesGastric cancer is diagnosed by fiber-optic endoscopy with biopsy. Studies to rule out specific organ metastases include endoscopic ultrasonography, computed tomography scans, chest radiographs, liver and bone scans, and liver biopsy. TreatmentRadical surgery to remove the tumor is possible in more than one third of patients. Even in the patient whose disease is not considered surgically curable, resection may temporarily ease symptoms and improve the patient’s response to chemotherapy and radiation therapy. The nature and extent of the lesion determine the type of surgery. Surgical procedures include gastroduodenostomy, gastrojejunostomy, partial gastric resection, and total gastrectomy. If metastasis has occurred, the omentum and spleen may have to be removed. Chemotherapy for GI tumors may help control signs and symptoms and prolong survival. Gastric adenocarcinomas respond to several agents, including fluorouracil, carmustine, doxorubicin, and mitomycin. Tumors that express HER2 antigens respond to treatment with trastuzumab (a monoclonal antibody that targets the human epidermal growth factor). Antispasmodics, antacids, and proton pump inhibitors may help relieve GI acidity and reflux symptoms. Antiemetics can control nausea, which intensifies as the tumor grows. Analgesics, sedatives, and tranquilizers are used to control pain and anxiety. Patient careNutritional intake is monitored, and the patient is weighed periodically. The health care provider initiates comprehensive clinical and laboratory investigations, including serial studies as indicated, if these have not already been done. The patient is prepared physically and emotionally for surgery, chemotherapy, or radiotherapy. During hospitalization, all general patient care concerns apply. Throughout the course of the illness, a high-protein, high-calorie diet with vitamin supplementation helps the patient avoid or recover from weight loss, malnutrition, and anemia, and promote wound healing. Frequent small meals are offered. To stimulate a poor appetite, antidepressant or steroid drugs may be administered. The patient is instructed in use of all drugs and the expected adverse effects of treatment, as well as in management strategies for these effects. Radiation therapy may cause nausea, vomiting, local skin damage, malaise, diarrhea, and fatigue. Chemotherapy may cause bone marrow suppression, infection, nausea, vomiting, mouth ulcers, and hair loss. During radiation or chemotherapy, oral intake is encouraged to remove toxic metabolites. Bland fruit juices, ginger ale, or other fluids, and prescribed antiemetics are provided to minimize nausea and vomiting; comfort and reassurance are offered as needed. The patient is advised to report persistent adverse reactions. The patient is encouraged to follow a normal routine as much as possible after recovery from surgery and during radiation therapy and chemotherapy. He should stop activities that cause excessive fatigue (at least temporarily) and incorporate rest periods. The patient should avoid crowds and people with known infections. Home-health care is provided as necessary. If curative treatment fails, palliative care and psychological support continues, with questions answered honestly but tactfully. Home or in-patient hospice care referrals are suggested as available. Synonym: stomach cancer hard cancerA cylindrical cancer composed of fibrous tissue. Synonym: scirrhous cancer; scirrhous carcinomahead and neck cancerSquamous cell carcinoma usually arising in the pharynx, oral cavity, or larynx. Research has shown links between human papillomavirus infection, tobacco smoking, and excessive alcohol use and head and neck cancers. interval cancerA cancer whose presence is diagnosed in the time between scheduled screening tests, e.g., a breast cancer that is not detected by regular periodic mammography, professional examination, and self-breast exams.kidney cancer Renal cell carcinoma.latent cancerA cancer that grows slowly and has no important health effect on the patient.lip cancerA squamous cell carcinoma of the lower lip usually seen in men or smokers.liver cancerMalignancy of the liver that results either from spread from a primary source or from primary tumor of the liver itself. The former is the more frequent cause. Male sex, hepatitis B or C, cirrhosis, and other liver diseases are predisposing factors. The liver is the most common site of metastatic spread of tumors that disseminate through the bloodstream. The prognosis for survival is from a few months to 1 yr. SymptomsThe disease may cause severe pain and tenderness; cachexia (loss of weight); and encephalopathy. Jaundice is common. The liver is enlarged, its surface is nodular, and a central depression or umbilications can often be detected. LUNG CANCER: Lung cancer seen endoscopically. The tumor is bleeding after being biopsied.lung cancerThe deadliest form of cancer in the U.S., responsible for about 159,000 deaths a year, according to statistics published by the ACS in 2011. The term includes four cell types: squamous cell (epidermoid) carcinoma, adenocarcinoma, large cell (anaplastic) cancer, and small cell (oat cell) cancer. The vast majority are caused by carcinogens in tobacco smoke, including second-hand smoke. Other risks include exposure to carcinogenic industrial and air pollutants (asbestos, uranium, arsenic, nickel, chromium, iron oxides, coal dust and radioactive dusts), radon gas concentrations, and familial susceptibility. Survival after diagnosis is poor: only one of seven patients lives for 5 years. However, if detected early (before spreading from the lungs), survival rates rise for most people. Radiofrequency ablation (RFA) is a promising therapy for patients with small lung tumors. Synonym: bronchogenic carcinoma See: illustrationTreatmentTreatment includes lung surgery, radiation therapy, and chemotherapy usually in combination. Patient careStaging determines the extent of the disease and aids in planning treatment and predicting the prognosis. Lung cancer is relatively difficult to cure but much easier to prevent. Children and adolescents should be discouraged from smoking tobacco products, and current smokers should be assisted in their efforts to quit, e.g., through referrals to local branches of the ACS, smoking-cessation programs, individual counseling, or group therapy. Screening and Public HealthChest x-rays do not show small, early cancers, but CT scanning can be used to screen people who have a long history of smoking and who are 50 to 60 years old. In this high-risk group, screening detects the disease in its early stages when it is most likely to be curable. However, since screening is very expensive, and since there are millions of smokers, the public health costs of mass screening are high compared with the cost of encouraging smokers to quit or of teaching teenagers not to start smoking. oral cavity cancerSquamous cell carcinoma of the mouth or tongue. Oral cavity cancers are only rarely caused by salivary gland tumors or sarcomas. ovarian cancerAny malignant growth in an ovary. About 85% to 90% of ovarian cancers arise from the surface epithelium of the ovary. In the U.S. in 2008, the ACS estimated there would be about 21,600 new patients diagnosed with ovarian cancer and about 15,200 deaths from the disease. Most cases (70%) are diagnosed when the disease is already at an advanced stage because early detection methods are still unsatisfactory. The early symptoms of the disease are often nonspecific and often mimic irritable bowel (constipation, vague abdominal pain, bloating). Initial laboratory studies (routine blood tests and x-rays) are often unremarkable. Currently, more women die of epithelial ovarian cancer than of all other gynecological cancers combined. A small percentage of patients with ovarian cancer may have a hereditary predisposition, e.g., they have BRCA-1 or BRCA-2 genes. High-risk women include those with multiple first-degree relatives (mother, sister, daughter) or second-degree relatives (aunt, grandmother, cousin) with histories of breast or ovarian cancer. Preventive surgery to remove the ovaries and fallopian tubes is the only way such women can significantly reduce their risk. Patient careOvarian cancer patients may feel threatened or vulnerable. They benefit from pretreatment support and education. Health care professionals address the patient's psychosocial needs while preparing her for treatment and manage the potential adverse reactions and the treatment and changes related to advancing disease. The first step in care is typically surgical debulking of the tumor. In this phase of care, the surgical oncologist attempts to remove not only the primary tumor, but also as many small tumorlets found within the peritoneum. The patient and family should be taught about the extensive surgical procedure and what to expect after surgery. After surgery, the patient is monitored for infection, circulatory complications, fluid and electrolyte imbalances, and pain. The patient who is to receive chemotherapy should be taught about major adverse reactions to the usual medications employed, taxanes and platinum-based drugs, such as fatigue, nausea and vomiting, hair loss, diarrhea, constipation, mucositis, neuropathy, arthralgia and myalgia, difficulty concentrating (chemobrain), and myelosuppression, as well as about measures to be taken to prevent and manage these problems. Chemotherapy may be given directly into the peritoneum or intravenously. Depression, anger, frustration, and anxiety are common. After the acute phase of treatment, the patient may undergo premature menopause; loss of fertility; alterations in body image, sexual function, and family relationships; impaired functional capacity; financial difficulties; and loss of spiritual well-being. The patient should be assessed for mood changes, inability to concentrate, fatigue, insomnia, and other symptoms of depression. Her medical history, current medications and treatments, nutritional status, pain rating, elimination pattern, and sexual history should be reviewed for factors that contribute to depression. Participating in a support group, meeting with mental health professionals, and taking an antidepressant or anti-anxiety medication can help alleviate depression and anxiety. Advancing or relapsing ovarian cancer may cause complications. These may include development of ascites, intestinal obstruction, deep vein thrombosis, malnutrition and cachexia, lymphedema, and pleural effusion. Current five-year survival rates for ovarian cancer are about 30% to 40%. If ovarian cancer recurs after treatment or fails to regress with treatment, palliative and end-of-life care may aid both patients and their families. cancer of the pancreasPancreatic cancer.pancreatic cancerCarcinoma of the pancreas. The American Cancer Society estimated there would be 37,700 new cases of the disease in the U.S. in 2008, with 34,300 deaths caused by the illness that year. Although the causes of pancreatic cancer are unknown, it has been found in more men than women, more blacks than whites, more smokers than nonsmokers, and more patients with a history of chronic pancreatitis and diabetes mellitus than without. When cancer occurs in the head of the pancreas, where it may obstruct the bile ducts and cause jaundice, the disease is most likely to be diagnosed at an early stage, when it may be most responsive to therapy. Surgical excision of the tumor and treatment with chemotherapy or radiotherapy may prolong survival in some patients. Only 4% of victims of pancreatic cancer survive 5 years. Synonym: carcinoma of the pancreas; cancer of the pancreaspancreatic carcinomaprimary cancerThe original cell or tissue type from which a metastatic cancer arises.prostate cancer See: prostate cancerscirrhous cancerHard cancer.skin cancerA broad term that includes basal cell carcinomas, squamous cell carcinomas, and melanomas. Together, these skin cancers are the most common cancers in the U.S. They are all associated with excessive exposure to ultraviolet light, e.g., sun exposure. See: basal cell carcinoma; squamous cell carcinoma; melanomaPatient careAccording to the U.S. Preventative Services Task Force (USPSTF), benefits from routine screening for skin cancers with a total body skin examination are unproven, even in high-risk patients. stomach cancerGastric cancer.terminal cancerWidespread or advanced cancer, from which recovery is not expected.testicular cancer, germ-cellAny of a group of testicular cancers that include choriocarcinomas, embryonal carcinomas, seminomas, spermatocytic seminomas, sex cord tumors, teratomas, and tumors with mixtures of several different malignant cell types.cancer of unknown primary siteDisseminated cancer in which the original tissue type is uncertain. Such cancers generally have poor prognoses. EtiologyPatients with such cancers are usually evaluated for tumors that might respond well to therapy, such as a lymphoma, a thyroid cancer, a germ cell tumor, or neoplasms of the breast or prostate. cancer of uterusA malignant neoplasm of the uterus, usually of the endometrium, found most often in women over 50. Other uterine cancers include those that arise in the muscular wall of the uterus (sarcomas), cervical cancers, and trophoblastic cancers. Symptoms may include post menopausal bleeding, bleeding between periods, and irregular, long, heavy periods. Pain during urination and during intercourse may be reported. Diagnosis of endometrial cancer is made by endometrial biopsy. The most common treatment is hysterectomy, although radiation and hormone therapy may be used. See: Bethesda System, The; cervical cancer; cervical intraepithelial neoplasiavulvar cancerAny malignant neoplasm of the vulva. Of these, 90% are squamous cell carcinomas; the rest are caused by adenocarcinomas, sarcomas, or Paget's disease. Vulvar cancer accounts for 4% of all gynecological malignancies. More than 50% of cases occur in postmenopausal women between 65 and 70. Generally, vulvar cancers are localized, slow-growing, and marked by late metastasis to the regional lymph nodes. Treatment may include surgery and/or radiation therapy. See: vulvectomy | Estimated New Cases | Estimated Deaths |
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| Male | Female | Male | Female |
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All sites | 745,180 | 692,000 | 294,120 | 271,530 | Oral cavity & pharynx | 25,310 | 10,000 | 5,210 | 2,380 | Esophagus | 12,970 | 3,500 | 11,250 | 3,030 | Stomach | 13,190 | 8,310 | 6,450 | 4,430 | Colon & rectum | 77,250 | 71,560 | 24,260 | 25,700 | Liver & intrahepatic bile duct | 15,190 | 6,180 | 12,570 | 5,840 | Pancreas | 18,770 | 18,910 | 17,500 | 16,790 | Lung & bronchus | 114,690 | 100,330 | 90,810 | 71,030 | Melanoma-skin | 34,950 | 27,530 | 5,400 | 3,020 | Breast | 1,990 | 182,460 | 450 | 40,480 | Uterine corpus | | 40,100 | | 7,470 | Ovary | | 21,650 | | 15,520 | Prostate | 186,320 | | 28,660 | | Urinary bladder | 21,230 | 17,580 | 9,950 | 4,150 | Kidney & renal pelvis | 33,130 | 21,260 | 8,100 | 4,910 | Brain & other nervous system | 11,780 | 10,030 | 7,420 | 5,650 | Thyroid | 8,930 | 28,410 | 680 | 910 | Non-Hodgkin lymphoma | 35,450 | 30,670 | 9,790 | 9,370 | Leukemia | 25,180 | 19,090 | 12,460 | 9,250 | *Excludes basal and squamous cell skin cancers and in situ carcinomas except urinary bladder. Carcinoma in situ of the breast accounts for about 67,770 new cases annually, and melanoma in situ accounts for about 54,020 new cases annually. Estimates of new cases are based on incidence rates from the NCI SEER program, 1995 to 2004. SOURCE: ©2008, American Cancer Society, Inc., Surveillance Research
Test | To Detect | Discussion |
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Breast self-examination | Breast cancer | Monthly self-examination by women is a noninvasive way to screen for changes in the breast. This method detects many benign and cancerous lumps, but its ability to prolong life is still debated. | Mammography | Breast cancer | Mammography is clearly effective screening in women over 50. Most mammograms are obtained by women in their 40s. The incidence of cancer is higher in later life, when mammography use tends to decline. | Digital rectal examination (DRE) | Colorectal cancer, prostate cancer | DRE is easy to perform and inexpensive but its cancer screening value is unproven; and, when it detects cancers, there is no proof that the test results in better patient outcomes. In addition, DRE detects a very small number of cancers, only those within the reach of the examiner. | Fecal occult blood test | Colorectal cancer | In people over 50, testing stool specimens for hidden bleeding detects many cancers; this detection results in earlier treatment and prolongation of life. The accuracy and value of the test relative to sigmoidoscopy and colonoscopy are uncertain. | Chest x-ray, sputum cytology, CT of the chest | Lung cancer | Prospective studies have yielded conflicting results for any method of screening for lung cancer in smokers, and the costs of screening, e.g., with computed tomography of the chest, may be prohibitive. The tests are of no value to nonsmokers. | Prostate specific antigen (PSA) | Prostate cancer | PSA testing detects many previously undetected prostate cancers but may result in increased death and disease due to complications from subsequent surgery. Refinements in its application may improve its usefulness as a screening tool. | Genetic testing | For predisposition to a variety of cancers | The predictive value of genetic testing for cancer is very small. Experts are debating the emotional and ethical consequences of genetic cancer screening tests. | *Note: Cancer screening tests are most likely to be useful when: (1) the cancer is common and deadly; (2) the test reliably distinguishes between healthy and diseased people; (3) early detection of the disease leads to improved treatments; (4) treatments are safe and well-tolerated; (5) the psychological effects of test results are addressed sensitively and carefully; (6) the tests are applied to people who will truly benefit from them.
cancer A disease of DNA. The term is used by the medical profession as a convenient and comprehensive label for all forms of MALIGNANT growths. There are two broad classes of cancers—those which arise from surface linings (CARCINOMAS) and those which arise from solid tissues (SARCOMAS). Cancers spread by local invasion and by lymph and blood spread (METASTASES) and their degree of malignancy is a measure of the rapidity with which they spread. It has long been believed that cancers start either as the result of small genetic changes to genes called tumour suppressor genes that restrain the ability of cells to divide, or to genes called oncogenes which suffer mutations. Research now suggests that many other abnormalities are probably involved. In early cancers there is much disruption of the chromosomes, some of which are duplicated or lost or truncated and parts fused together. Chromosomal instability appears to be an important element. It is only a matter of time before cancers are classified by their pattern of gene abnormality. Although some aspects of the biology of cancers remain obscure, recent years have shown remarkable advances in the effective treatment of many cancers. See also CANCER STEM CELLS.cancer a disease affecting the growth rate of affected tissues, in which the control mechanisms of cells become altered and the cells divide to form neoplastic growths or tumours. ‘Benign’ tumours consist of well-differentiated cells similar to those in the surrounding tissues and are usually harmless unless located in regions where no operation is possible. ‘Malignant’ tumours are dangerous and usually contain embryonic cells, which are capable of floating away and forming new malignant growths in other sites. Little is known of the cause of cancer, though exposure to CARCINOGENS such as nicotine and mustard gas or the presence of certain microorganisms are possible causes. Radiation, surgery and chemotherapy are all used in the treatment of cancers. can·cer (CA) (kan'sĕr) General term frequently used to indicate any of various types of malignant neoplasms, most of which invade surrounding tissues, may metastasize to several sites, and are likely to recur after attempted removal and kill the patient unless adequately treated. [L. a crab, a cancer]Patient discussion about cancerQ. how many types of cancer are they? A. There are over 200 different types of cancer. You can develop cancer in any body organ. There are over 60 different organs in the body where you can get a cancer. Each organ is made up of several different tissue types. For example, there is usually a surface covering of skin or epithelial tissue. Underneath that there will be some connective tissue, often containing gland cells. Underneath that there is often a layer of muscle tissue and so on. Each type of tissue is made up of specific types of cells. Cancer can develop in just about any type of cell in the body. So there is almost always more than one type of cancer that can develop in any one organ. Q. why does it call "cancer"?can you treat cancer? A. the name came from the appearance of the cut surface of a solid malignant tumour, with the veins stretched on all sides as the animal the crab has its feet, whence it derives its name. Hippocrates first called it in that name after describing few types of cancer. some of the cancers are treatable but that is a big subject. there are some very nice videos here on the site that can give you a clue about that. just search them there ^ :) Q. Cancer - incurable? When i was surfing the internet for the incurable disease, i found CANCER is one among them. Is there not a medicine found yet? Really is it incurable?A. I like to share with you what i read from a book it said 'With modern day treatments many cancers are completely cured but unfortunately there are still many others which are not. Although it is not always possible to be certain, doctors are often able to tell whether or not a particular cancer might be cured. Even if cancer is incurable they will usually still offer treatment in the hope of prolonging life and, controlling, symptoms.' http://www.youtube.com/watch?v=FOBvDTf9ohQ More discussions about cancerFinancialSeeCACANCER
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CANCER➣Computer Analysis of Nonlinear Circuits, Excluding Radiation |
cancer Related to cancer: lung cancer, Cancer treatmentSynonyms for cancernoun growthSynonyms- growth
- tumour
- carcinoma
- malignancy
noun evilSynonyms- evil
- corruption
- rot
- sickness
- blight
- pestilence
- canker
Synonyms for cancernoun any malignant growth or tumor caused by abnormal and uncontrolled cell divisionSynonyms- malignant neoplastic disease
Related Words- malignant neoplasm
- malignant tumor
- metastatic tumor
- lymphoma
- carcinoma
- cancer of the blood
- leucaemia
- leukaemia
- leukemia
- sarcoma
noun (astrology) a person who is born while the sun is in CancerSynonymsRelated Words- individual
- mortal
- person
- somebody
- someone
- soul
- astrology
- star divination
noun a small zodiacal constellation in the northern hemisphereRelated Wordsnoun the fourth sign of the zodiacSynonymsnoun type genus of the family CancridaeSynonymsRelated Words- arthropod genus
- Cancridae
- family Cancridae
- Cancer magister
- Dungeness crab
- Cancer irroratus
- rock crab
- Cancer borealis
- Jonah crab
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