Antineoplastic

any one of a group of synthetic or natural substances used in the treatment of malignant tumors. Antineoplastics include alkylating agents (embichine, novembichin, Chlorbutin [chlorambucil], dopan, sarcolysine, Cyclophosphane [cyclophosphamide], myelosan), antimetabolites (methotrexate, 6-mercaptopurine, 5-fluorouracil), antibiotics (bruneomycin, rubomycin), and plant alkaloids (Colchamine [Colcemid], vinblastine, vincristine). These substances arrest the process of mitosis. In addition, enzymes and hormonal preparations are used, including corticosteroids and female and male sex hormones.

Antineoplastics are used only with certain types of tumors. The histological structure that a tumor of a particular organ has is especially significant. There is no universal antineoplastic preparation. As a rule, the effect of the preparation is inversely proportional to the mass of the tumor, that is, the preparation is more easily effective with a small tumor than with a large one. Treatment with antineoplastics is based on the differences between the biochemical properties of normal and tumoral tissues and is directed predominantly toward suppressing the accelerated reproduction of tumoral cells. The differences between normal and tumoral tissues are principally quantitative—rapid cell reproduction is characteristic not only of tumoral elements but also of normal cells of the hematopoietic organs, intestinal epithelium, and skin.

Antineoplastics also affect normal tissues when they act on a tumor. Many antineoplastics are toxic and produce side effects that may or may not be associated with the mechanism of suppressing cell reproduction. These side effects include nausea, vomiting, loss of appetite, diarrhea, stomatitis, and a decrease in the number of leukocytes, thrombocytes, and erythrocytes in the blood. In some cases, this results in the limitation of the dosage or even suspension of treatment.

Antineoplastics are either injected intravenously, administered orally, or injected into the pleural or abdominal cavities. The preparation has a local effect when the injection is intracavitary, although it is to one degree or another absorbed into the blood. In treating skin tumors, antineoplastics can be applied locally. It is possible to increase the effectiveness of the treatment and decrease the toxic effects of the preparation by special injection methods, when the antineoplastic is injected into the vessels that supply the tumor with blood. Antineoplastics are usually administered in stages, with varying time periods separating the stages. Sometimes there is a delayed reaction and the effect of the preparation only occurs after the completion of one stage of treatment.

Polychemotherapy is promising in the treatment of tumors. It consists in the simultaneous or successive use of several preparations that differ in the mechanism of their effect and in their toxic side effects. There has been progress in the treatment of children stricken with acute lymphoid leukemia, largely because of the introduction of therapy combined with antineoplastic preparations. Antineoplastics are also used together with other methods of tumor treatment, for instance, during preoperative and postoperative periods, or with radiotherapy.

REFERENCES

Larionov, L. F. Khimioterapiia zlokachestvennykh opukhoki. Moscow, 1962.
Blokhin, N. N., and N. I. Perevodchikova. “Nekotorye etapy klinicheskoi khimioterapii opukholevykh zabolevanii.” Vestnik AMN SSSR, 1967, no. 5.

V. I. ASTRAKHAN

antineoplastic

[an″te-, an″ti-ne″o-plas´tik] inhibiting the maturation and proliferation of malignant cells.antineoplastic agent.antineoplastic therapy a regimen that includes chemotherapy, aimed at destruction of malignant cells using a variety of agents that directly affect cellular growth and development. Chemotherapy is but one of a variety of methods available in the treatment of cancer. Cancers particularly responsive to chemotherapy include choriocarcinoma, a highly malignant form of cancer that originates in the placenta; testicular carcinoma; and burkitt's lymphoma, a malignancy most often found in African children. Combinations of drugs have successfully controlled acute leukemia in children and in persons with advanced stages of hodgkin's disease.Types of Antineoplastic Agents. The chemicals and drugs used in the treatment of cancer may be divided into several main groups. The first group, the alkylating agents, are capable of damaging the DNA of cells, thereby interfering with the process of replication; they are cell cycle phase nonspecific. Among these are busulfan, cyclophosphamide, ifosfamide, and thiotepa; the nitrogen mustardschlorambucil, mechlorethamine, and melphalan; and the nitrosoureascarmustine, lomustine, semustine, and streptozocin.
The second group of drugs is the antimetabolites; as the name suggests, they interfere with the cancer cell's metabolism. Some replace essential metabolites without performing their functions, while others compete with essential components by mimicking their functions and thereby inhibiting the manufacture of protein in the cell. Antimetabolites are cell cycle phase specific (S phase). Included in this group are capecitabine, cladribine, cytarabine, floxuridine, fludarabine, fluorouracil, mercaptopurine, methotrexate, and thioguanine.
The third group is the antitumor antibiotics. These agents have been isolated from microorganisms and affect the function and/or synthesis of nucleic acids; they are cell cycle phase nonspecific. This group includes bleomycin sulfate, dactinomycin, daunorubicin, doxorubicin, epirubicin, idarubicin, mitomycin, mitoxantrone, pentostatin, plicamycin, and streptozocin.
The fourth group is the alkaloids; the most important of which are the vinca alkaloids. They are cell cycle phase specific, exerting their effect during the M phase of cell mitosis and causing metaphase arrest. Included in this group are vinblastine, vincristine, vindesine, and vinorelbine tartrate.
The fifth group is the hormones and antihormones, which create an unfavorable environment for cancer cell growth. Hormones used in antineoplastic therapy include estrogens, androgens, progestins, and corticosteroids. antihormones include aminoglutethimide, chlorotrianisene, flutamide, goserelin, leuprolide, and tamoxifen.
There are a variety of other drugs, some whose mechanisms of action are known and others for whom the mechanism is unknown. Plant derivatives include the podophyllotoxin derivatives etoposide and teniposide, as well as paclitaxel, a derivative of the Pacific yew tree. Platinum coordination compounds include carboplatin and cisplatin. Other agents include asparaginase, dacarbazine, hydroxyurea, the interferons, levamisole, mitotane, procarbazine, and tretinoin.Patient Care. The drugs used in antineoplastic therapy are highly toxic and likely to produce troublesome or even extremely dangerous reactions; they should be administered only by qualified professionals. They may be given singly or in combination, depending on the type of malignancy and the stage of its development. The complexity of this type of therapy, particularly when used in conjunction with surgery or radiation therapy, demands a team of specialists, including medical oncologists, radiotherapists, nurse clinicians, and clinical pharmacologists, working cooperatively to accomplish the goals of the prescribed regimen.
It is especially important that members of the team be aware of and capable of dealing with the toxicity inherent in antineoplastic therapy. The management of drug toxicities requires a delicate balance between effective dosage to destroy malignant cells and the individual patient's tolerance of drug and dosage. Anorexia, nausea, and vomiting are among the milder but more troublesome effects of antibiotics, alkylating agents, and antimetabolites. It is necessary to work with each patient and help establish a routine that will incorporate administration of the drug, taking an antiemetic, and spacing meals so that adequate nutrition is provided and excessive weight loss is avoided. Stomatitis and diarrhea are also likely to appear as early signs of toxicity from antimetabolic and antibiotic drug therapy.
Drugs that suppress bone marrow function produce leukopenia, which in turn increases susceptibility to infection. If the patient is also receiving an immunosuppressant such as prednisone, resistance to infection is further compromised. The patient will need adequate rest, good nutrition, good habits of personal cleanliness, and avoidance of contact with those who have infectious diseases. If an infection does develop, it should receive prompt attention to minimize its effects and inhibit its progress. It may be necessary to alter the dosage of the antineoplastic drug until the infection subsides.
Bone marrow-suppressing drugs can also affect the platelet count, reducing it to a level at which bleeding can readily occur. Normal clotting is impaired by some cancer therapeutic agents and there is therefore the danger of internal bleeding anywhere in the body. Should the situation become severe, the drug dosage may need to be reduced or stopped altogether and platelet transfusions may be given.
Hormonal therapy frequently is accompanied by fluid retention. Measurement of intake and output, daily weight measurement, and observation for signs of surface edema or congestive heart failure are essential parts of patient care. Care of the patient with edema must include meticulous skin care. If diuretics are given, the patient must be watched for signs of potassium depletion. Another side effect of hormonal therapy may be changes in secondary sexual characteristics. These can be particularly embarrassing and emotionally disturbing to the patient.
Neurologic disorders may result from treatment with the plant alkaloids. These conditions may manifest themselves as impaired sensation, loss of coordination, and severe constipation. Although these neurological effects usually are reversible, especially if caught in the early stages, it may take months for the nerve cells to recover and resume normal function.
Many antineoplastic drugs cause alopecia (hair loss). This side effect can drastically alter the patient's body image and can be very disturbing psychologically. Wigs, hairpieces, and various head coverings can be used to mask the hair loss.

an·ti·ne·o·plas·tic

(an'tē-nē'ō-plas'tik), Preventing the development, maturation, or spread of neoplastic cells.

antineoplastic

(ăn′tē-nē′ə-plăs′tĭk, ăn′tī-)adj. Inhibiting or preventing the growth or development of malignant cells.

an′ti·ne′o·plas′tic n.

antineoplastic

adjective Referring to an agent or mechanism that lyses or inhibits tumours.
noun An agent that attenuates, kills or inhibits tumour growth.

antineoplastic

adjective Referring to an antineoplastic agent or mechanism noun Chemotherapeutic agent, see there.

an·ti·ne·o·plas·tic

(an'tē-nē'ō-plas'tik) Preventing the development, maturation, or spread of neoplastic cells.

antineoplastic

Able to control the growth or spread of cancers (neoplasms).

Antineoplastic

A drug used to inhibit the growth and spread of cancerous cells.Mentioned in: Priapism

an·ti·ne·o·plas·tic

(an'tē-nē'ō-plas'tik) Preventing the development, maturation, or spread of neoplastic cells.

antineoplastic

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antineoplastic

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Antineoplastic

Antineoplastic

REFERENCES

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Synonyms for antineoplastic

noun any of several drugs that control or kill neoplastic cells

Synonyms

Related Words

adj used in the treatment of cancer

Synonyms