thyroid cancer

Thyroid Cancer

Definition

Thyroid cancer is a disease in which the cells of the thyroid gland become abnormal, grow uncontrollably, and form a mass of cells called a tumor.

Description

Thyroid cancer is grouped into four types based on how its cells appear under a microscope. The types are papillary, follicular, medullary and anaplastic thyroid cancers. They grow at different rates and can spread to other parts of the body if left untreated.The thyroid is a hormone-producing butterfly-shaped gland located in the neck at the base of the throat. It has two lobes, the left and the right. The thyroid uses iodine, a mineral found in some foods, to make several of its hormones. Thyroid hormones regulate essential body processes such as heart rate, blood pressure, body temperature, metabolism; and affect the nervous system, muscles and other organs. These hormones also play an important role in regulating childhood growth and development.Diseases of the thyroid gland affect millions of Americans. The most common diseases of the thyroid are either hyperthyroidism (Graves' disease) or hypothyroidism, an overactive or an underactive gland, respectively. Sometimes lumps or masses may develop in the thyroid, and although most (ninety-five percent) of these lumps or nodules are noncancerous (benign), all thyroid lumps should be taken seriously. The American Cancer Society estimates that the approximately 17,200 new cases of thyroid cancer that occur in the United States account for 1% of all cancers.Women are three times more likely to develop thyroid cancer than men. Although the disease affects teenagers and young adults, most people that develop thyroid cancer are over 50 years of age.

Causes and symptoms

The exact cause of thyroid cancer is not known; but it is more common in whites than in African Americans. Radiation was used in the 1950s and 1960s to treat acne and to reduce swelling in infections of the tonsils, adenoids and lymph nodes. It has been proven that this exposure is a risk factor for thyroid cancer. In some areas of the world, diets are low in iodine. Papillary and follicular cancers occur more frequently in these areas. Iodine deficiency is not a large problem in the United States because iodine is added to table salt and other foods. Approximately 7% of thyroid cancer are caused by the alteration (mutation) of a gene called the RET gene, which can be inherited.Symptoms are rare so the lump is not usually painful. The symptoms of thyroid nodules are:

a lump or nodule that can be felt in the neck is the most frequent sign of thyroid cancer
the lymph nodes may be swollen and the voice may become hoarse because the tumor presses on the nerves leading to the voice box
some patients experience a tight or full feeling in the neck and have difficulty breathing or swallowing

Diagnosis

Physicians use several tests to confirm the suspicion of thyroid cancer, to identify the size and location of the lump and to determine whether the lump is noncancerous (benign) or cancerous (malignant). Blood tests such as the thyroid stimulating hormone (TSH) test check thyroid function. These are drawn by a technician with a needle and takes a few minutes. It take several days to be interpreted by a pathologist. Calcitonin is produced by the C cells (parafollicular cells) of the thyroid gland when the parafollicular cells of the thyroid become cancerous. Blood calcitonin levels are used to confirm the diagnosis of medullary thyroid cancer if it is suspected.Computed tomography scan (CT scan) or an ultrasonography (ultrasound scan) are imaging tests used to produce a picture of the thyroid and usually last less than one hour. A radiologist usually interprets the results within 24 hours. In ultrasonography, high-frequency sound waves are bounced off the thyroid. The pattern of echoes that is produced by these waves is converted into a computerized image on a television screen. This test can determine whether the lumps found in the thyroid are benign fluid-filled cysts or solid malignant tumors.A radioactive scan may take several hours and can be used to identify any abnormal areas in the thyroid by giving the patient a very small amount of radioactive iodine, which can either be swallowed or injected into the thyroid. Since the thyroid is the only gland in the body that absorbs iodine, the radioactive iodine accumulates there. An x-ray image can then be taken or an instrument called a "scanner" can be used to identify areas in the thyroid that do not absorb iodine normally. These abnormal spots are called "cold spots" and further tests are performed to check whether the cold spots are benign or malignant tumors. If a significant amount of radioactive iodine is concentrated in the nodule, then it is termed "hot" and is usually benign. Again a radiologist interprets the results within a day.The most accurate diagnostic tool for thyroid cancer is a biopsy. In this process a sample of thyroid tissue is withdrawn and examined under a microscope by a pathologist. This usually takes a day or so. The tissue samples can be obtained either by drawing out a sample of tissue through a needle (needle biopsy) or by surgical removal of the nodule (surgical biopsy). A needle biopsy takes a few minutes and can be done by any trained physician, usually a radiologist. The surgical biopsy is done by a surgeon under general anesthesia with the help of an anesthesiologist and will take a few hours. If thyroid cancer is diagnosed, further tests may be done to learn about the stage of the disease and help doctors plan appropriate treatment.

Treatment

The aggressiveness of each type of thyroid cancer is different. Cancer staging considers the size of the tumor, whether it has grown into surrounding lymph nodes and whether it has spread to distant parts of the body (metastasized). Age and general health status are also taken into account. In patients less than 45 years old there are only two stages. I papillary or follicular type thyroid cancer, stage I refers to patients without evidence of cancer that has spread to the body. Stage II refers to patients with spread of cancer outside the thyroid gland. In patients over 45, patients with tumors smaller than one cm are classified as stage I, those with tumors not broken through the capsule (covering) of the thyroid belong to stage II, those with tumors outside the capsule or lymph node involvement are called stage III and those with spread outside the thyroid area are stage IV. In medullary—type thyroid cancer, stage I and IV are the same. Stage II consists of patients with tumors greater than one cm and stage III comprises patients with lymph node involvement.The papillary type (60-80% of all thyroid cancers) is a slow-growing cancer that develops in the hormone-producing cells (that contain iodine) and can be treated successfully. The follicular type (30-50% of thyroid cancers) also develops in the hormone-producing cells, has a good cure rate but may be difficult to control if the cancer invades blood vessels or grows into nearby structures in the neck. The medullary type (5-7% of all thyroid cancers) develops in the parafollicular cells (also known as the C cells) that produce calcitonin, a hormone that does not contain iodine. Medullary thyroid cancers are more difficult to control because they often spread to other parts of the body. The fourth type of thyroid cancer, anaplastic (2% of all thyroid cancers), is the fastest-growing and is usually fatal because the cancer cells rapidly spread to the different parts of the body.More than 90% of patients who are treated for papillary or follicular cancer will live for 15 years or longer after the diagnosis of thyroid cancer. Eighty percent of patients with medullary thyroid cancer will live for at least 10 years after surgery. Only 3-17% of patients with anaplastic cancer survive for five years.Like most cancers, cancer of the thyroid is best treated when it is found early by a primary physician. Treatment depends on the type of cancer and its stage. Four types of treatment are used: surgical removal, radiation therapy, hormone therapy and chemotherapy. Surgical removal is the usual treatment if the cancer has not spread to distant parts of the body.The surgeon may remove the side or lobe of the thyroid where the cancer is found (lobectomy) or all of it (total thyroidectomy). If the adjoining lymph nodes are affected, they may also be removed during surgery. When the thyroid gland is removed and levels of thyroid hormones decrease, the pituitary gland starts to produce TSH that stimulates the thyroid cells to grow.A radiation-oncologist uses radiation therapy with high-energy x-rays to kill cancer cells and shrink tumors. The radiation may come from a machine outside the body (external beam radiation), or the patient may be asked to swallow a drink containing radioactive iodine. Because the thyroid cells take up iodine, the radioactive iodine collects in any thyroid tissue remaining in the body and kills the cancer cells. A hematologist-oncologist uses chemotherapy either as a pill or an injection through a vein in the arm.

Alternative treatment

Hormone therapy uses hormones after surgery to stop this growth and the formation of new cancerous thyroid cells. To prevent cancerous growth, the natural hormones that are produced by the thyroid are taken in the form of pills. Thus, their levels remain normal and inhibit the pituitary gland from making TSH. If the cancer has spread to other parts of the body and surgery is not possible, hormone treatment is aimed at killing or slowing the growth of cancer cells throughout the body.

Key terms

Biopsy — The surgical removal and microscopic examination of living tissue for diagnostic purposes.Calcitonin — A hormone produced by the parafollicular cells (C cells) of the thyroid. The main function of the hormone is to regulate calcium levels in body serum.Chemotherapy — Treatment of cancer with synthetic drugs that destroy the tumor either by inhibiting the growth of the cancerous cells or by killing them.Hormone therapy — Treatment of cancer by inhibiting the production of hormones such as testosterone and estrogen.Hyperthyroidism — A condition in which the thyroid is overactive due to overstimulation of the thyroid cells.Hypothyroidism — A condition in which the thyroid gland is underactive.Lobectomy — A surgical procedure that removes one lobe of the thyroid.Radiation therapy — Treatment with high-energy radiation from x-ray machines, cobalt, radium, or other sources.Total thyroidectomy — A surgical procedure that removes the entire thyroid gland.A powerful phytochemical, lycopene, gives tomatoes their red color and appears to act as an antioxidant in the body, repairing damaged cells and scavenging free radicals, the molecules responsible for most types of degenerative diseases and aging. Antioxidants such as lycopene help inhibit DNA oxidation, which can lead to certain forms of cancer. Lycopene is a normal constituent of human blood and tissues, where it is found in greater concentrations than beta-carotene or any other carotenoid. Tomatoes, including cooked or processed tomatoes, tomato juices, soups, sauces, paste and ketchup, contain more lycopene than any other food. Guava, rose hip, watermelon and grapefruit also contain lycopene.Other antioxidants are: vitamin E (Dosage: 400 IU daily), vitamin C (Dosage: 1,000 to 4,000 mg daily), beta carotene (Dosage: 15 mg (25,000 IU) daily), lutein (Dosage: 6 to 20 mg daily), pycnogenol (Dosage: 25 to 50 mg daily), green tea (Dosage: 300 to 400 mg of green tea polyphenols daily), grape-seed extract (Dosage: 100 mg daily), alpha lipoic acid (Dosage: 50 to 200 mg daily), N-acetylcysteine (Dosage: 600 mg daily) and selenium (Dosage: 200 to 400 mcg daily). Pregnant women should consult a physician before taking any medication.

Prevention

Because most people with thyroid cancer have no known risk factor, it is not possible to completely prevent this disease. However, inherited cases of medullary thyroid cancer can be prevented and radiation to the neck is avoided. If a family member has had this disease, the rest of the family can be tested and treated early. The National Cancer Institute recommends that a doctor examine anyone who has received radiation to the head and neck during childhood at intervals of one or two years. The neck and the thyroid should be carefully examined for any lumps or enlargement of the nearby lymph nodes. Ultrasound may also be used to screen for the disease in people at risk for thyroid cancer.

Resources

Organizations

National Cancer Institute (National Institutes of Health). 9000 Rockville Pike, Bethesda, MD 20892. (800) 422-6237. http://www.nci.nih.gov.

thyroid cancer

A general term for a malignant epithelial lesion of the thyroid with 45,000 new cases/year (US), and 1700 deaths. Women account for three-fourths of cases; current, overall 5-year survival with treatment is 95+%. Carcinoma of the thyroid is divided into histologically—and usually clinically—distinct subtypes in order of increasing aggressiveness: papillary carcinoma, follicular carcinoma, medullary carcinoma, poorly differentiated and undifferentiated (anaplastic) carcinoma.
Clinical
Palpable neck mass (0.14% of all palpable neck masses ultimately prove to be TC).

Prognosis
Uncertain; the initial (5-year) prognosis depends on the histological subtype, but may recur decades later; administration of TSH stimulates remaining thyroid tissue and prevents symptomatic hypothyroidism, which occurs when thyroid hormone is discontinued, and stimulates radioiodine uptake by residual normal and cancerous thyroid tissue.
Staging, carcinoma of thyroid
pTX—Primary tumour cannot be assessed.
pT0—No evidence of primary tumour.
pT1a— = 10 mm limited to thyroid.
pT1b— = 20 mm, > 10 mm limited to thyroid.
pT2—> 20 mm, ≤ 40 mm limited to thyroid.
pT3—> 40 mm limited to thyroid or any tumour with minimal extrathyroidal extension—e.g. extension to sternothyroid muscles or perithyroid soft tissues.
All anaplastic carcinomas are considered pT4 tumours:
pT4a—Tumour invades beyond thyroid capsule and invades any of: subcutaneous soft tissues, larynx, trachea, oesophagus, recurrent laryngeal nerve.
pT4b—Tumour invades prevertebral fascia, mediastinal vessels or encases carotid artery.
Multifocal tumours (= 2 foci) of all histological types should be designated (m), the largest focus determining the classification—e.g., pT2(m).
pNX—Cannot assess regional lymph nodes.
pN0—No regional nodes involved.
pN1a—Metastasis in level-VI (pretracheal, paratracheal and prelaryngeal/Delphian) lymph nodes.
pN1b—Metastasis in other unilateral, bilateral or contralateral cervical (levels I, II, III, IV or V), or retropharyngeal or superior mediastinal lymph nodes.
M1—Distant metastases proven histologically (MX is not used in TNM v7, which itconsiders as proof that M0 cannot be arrived at by surgical pathology alone).
RX—Cannot assess presence of residual primary tumour.
R0—No residual primary tumour.
R1—Microscopic residual primary tumour.
R2—Macroscopic residual primary tumour.

thyroid cancer

Thyroid carcinoma Oncology A malignant epithelial lesion of the thyroid that affects 14,000/yr–US, 1100 deaths/yr; ♀ account for 77% of new cases and 61% of deaths; current overall 5-year survival with treatment is 95% Risk factors Persons exposed to the upper body–especially head & neck radiation during childhood; persons with a family Hx of TC or MEN 2 syndrome; the risk of radiation-induced thyroid nodularity and CA ↑ with radiation dose and ↓ the older the person was at the time of irradiation; medullary TC, which comprises about 10% of all TCs, is inherited in 25% of cases as part of MEN 2 syndrome Clinical Palpable neck mass Note 0.14% of palpable neck masses ultimately prove to be TC Management Surgery, radioiodine Prognosis Uncertain; recurrences may occur decades later; administration of TSH stimulates remaining thyroid tissue, and prevents symptomatic hypothyroidism, which occurs when thyroid hormone is discontinued, and stimulates radioiodine uptake by residual thyroid and thyroid CA tissue. See Thyrotropin.

Thyroid Cancer

DRG Category:	626
Mean LOS:	3 days
Description:	SURGICAL: Thyroid, Parathyroid, and Thyroglossal Procedures With CC
DRG Category:	644
Mean LOS:	4.9 days
Description:	MEDICAL: Endocrine Disorders With CC

Thyroid cancer is the most common endocrine cancer, and the number of new cases in the United States is increasing annually by 3% per 100,000 individuals. The American Cancer Society estimated that in 2013, 60,220 new cases of thyroid cancer were diagnosed: 45,310 in women and 14,910 in men. Most thyroid nodules or tumors develop from thyroid follicular cells; 95% of these nodules and tumors are benign. The remaining 5% of thyroid nodules or tumors are cancerous, and there are several forms of thyroid cancer. Papillary carcinoma is the most common form of primary thyroid cancer. It is also the slowest growing thyroid cancer and is usually multifocal and bilateral in distribution. Papillary carcinoma metastasizes slowly into the cervical lymph nodes and the nodes of the mediastinum and lungs. Follicular cancer is the next most common form. It is more likely to recur than other forms; it generally metastasizes to the regional lymph nodes and is spread by the blood to distant areas such as the bones, liver, and lungs. More than 90% of patients treated for either papillary or follicular carcinoma will live for 15 years or longer after their diagnosis.

Anaplastic carcinoma of the thyroid is a less common form of thyroid cancer and is resistant to both surgical resection and radiation; the 5-year survival rate is between 3% and 17%. Anaplastic cells metastasize quickly, invade the trachea and surrounding tissues, and compress vital structures. Medullary cancer is even less common (3% to 4% of thyroid cancers); it originates in the parafollicular cells of the thyroid. Metastasis occurs to the bones, liver, and kidneys if the disease is not treated. In addition to metastases, other life-threatening complications include compression of surrounding structures (particularly in the neck), leading to difficulty swallowing and breathing. Surgery can cure medullary thyroid cancer; 86% have 5-year survival rate, and 65% survive 10 years or more.

Causes

While most individuals with thyroid cancer have no apparent risk factors, the following factors may be involved: family history of goiter, family history of thyroid disease, female gender, and Asian race. People who have been exposed to radiation therapy to the neck are particularly susceptible to thyroid cancer, including those exposed to low-dose radiation as children and others exposed to high-dose radiation for malignancies. About 25% of individuals who had radiation in the 1950s to shrink an enlarged thymus gland, tonsils, or adenoids develop thyroid nodules; approximately 25% of those with nodules actually develop thyroid cancer (6% of those exposed to neck radiation in the first place). Other causes of thyroid cancer include prolonged secretion of thyroid-stimulating hormone (TSH) because of radiation, heredity, or chronic goiter.

Genetic considerations

Most cases of thyroid cancer are sporadic (75% in a Swedish study and 60% in a French national registry). Rearrangements of the RET or NTRK1 genes to form chimeric oncogenes are observed in about 50% of cases. Familial cases are usually due to the presence of multiple endocrine neoplasia type II (MEN II), a group of autosomal dominantly inherited disorders caused by mutations in the RET oncogene. Familial susceptibility has also been mapped to 19p and 2q21.

Gender, ethnic/racial, and life span considerations

Although benign thyroid nodules and thyroid cancers can occur in people of all ages, those between ages 30 and 50 are most likely to develop papillary and follicular thyroid cancer. Women are three times as likely as men to have thyroid cancer. Ethnicity and race have no known effects on the risk for thyroid cancer.

Global health considerations

Globally, thyroid cancer is more common in females than in males. The incidence of thyroid cancer is approximately 3 per 100,000 females, as compared to 1 per 100,000 males. People in developed nations have two to three times the incidence of thyroid cancer as compared to people in developing nations.

Assessment

History

Most patients present with an asymptomatic neck mass. They may also have complaints of neck discomfort, hoarseness, dysphagia (difficulty swallowing), feeling as if they are “breathing through a straw,” and rapid nodule growth. Elicit a family history because some forms of thyroid cancer are inherited. If the thyroid has been completely destroyed by cancer cells, the patient may report a history of sensitivity to cold, weight gain, and apathy from hypothyroidism. If the thyroid has become overstimulated, the patient may describe signs of hyperthyroidism: sensitivity to heat, nervousness, weight loss, and hyperactivity. Changes in thyroid function may also lead to gastrointestinal changes such as diarrhea and anorexia.

Physical examination

The most common symptoms are a palpable thyroid nodule, hoarseness, difficulty swallowing, and neck discomfort. Observe the patient’s neck, noting any mass or enlargement. Patients with anaplastic thyroid cancer may have a rapidly growing tumor that distorts the neck and surrounding structures. Palpate the thyroid gland for size, shape, configuration, consistency, tenderness, and presence of any nodules. Describe the number of nodules present and whether the nodule is smooth or irregular, soft or hard, or fixed to underlying tissue. Note the presence of enlarged cervical lymph nodes, which occurs in 25% of patients with the disease. Auscultation may reveal bruits if the thyroid enlargement results from an increase in TSH, which increases thyroid circulation and vascularity.

Psychosocial

Assess the patient’s ability to cope with the sudden illness and the diagnosis of cancer. Determine what a diagnosis of cancer means to the patient. Consider the type of cancer (and the speed of cancer growth) when assessing the patient’s and family’s response to the disease.

Diagnostic highlights

Test	Normal Result	Abnormality With Condition	Explanation
Fine-needle aspiration (FNA) biopsy	Microscopic viewing reveals no cancerous cells	Microscopic viewing reveals cancer cells	A thin needle is placed directly into the nodule several times to sample different areas; 5% of FNA biopsies reveal cancer, while 60% to 80% clearly show that the nodule is benign
Thyroid scan	Homogenous uptake of radioactive tracer; normal size and shape of thyroid	Abnormal areas of the thyroid may contain less radioactivity (cold nodules with decreased uptake) or more radioactivity (hot nodules with increased uptake)	A small quantity of radioactive iodine is taken orally or intravenously; after the chemicals concentrate in the thyroid, a special camera measures the amount of radiation in the thyroid gland
Sentinel lymph node biopsy	Sentinel node (first node into which the tumor drains) is cancer free	Lymph nodes containing cancer will absorb dye and radioactive material	Radioactive tracer and blue dye is injected into tumor and will travel to lymph nodes with cancer; is done to determine if the sentinel node is cancer free
Thyroid-stimulating hormone (TSH; thyrotropin)	< 4 mlU/L	Normal or elevated	Used to determine if radioactive iodine will work as therapy
Serum calcitonin	< 40 pg/mL	Increased in medullary cancer of thyroid; levels 500 to 2,000 pg/mL are often associated with cancer	Thyroid gland polypeptide hormone produced by thyroid even when no mass is palpable

Other Tests: Sonogram, computed tomography scan, magnetic resonance imaging, octreotide scan used for determining cancer staging and spread, serum calcium

Primary nursing diagnosis

Diagnosis

Ineffective airway clearance related to swelling and obstruction

Outcomes

Respiratory status: Gas exchange; Respiratory status: Ventilation; Symptom control behavior; Treatment behavior: Illness or injury; Comfort level

Interventions

Airway management; Anxiety reduction; Oxygen therapy; Airway suctioning; Airway insertion and stabilization; Cough enhancement; Mechanical ventilation; Positioning; Respiratory monitoring

Planning and implementation

Collaborative

Most physicians prescribe surgical treatment of thyroid cancer, with the definitive treatment depending on the size of the nodule. Surgical interventions range from a thyroid lobectomy for cancers smaller than 1 cm that show no signs of metastasis to a total thyroidectomy and, possibly, a modified neck dissection if lymph nodes need to be removed. To prevent complications after the thyroidectomy, careful monitoring for airway obstruction and stridor is essential. A tracheostomy tray should be kept near the patient at all times during the immediate recovery period. In addition, monitor for signs of thyrotoxicosis (tachycardia, diaphoresis, increased blood pressure, anxiety) and hypocalcemia (tingling of the fingers and toes, carpopedal spasms, and convulsions). The surgical dressing and incision also need to be assessed for excessive drainage or bleeding during the postoperative period. If the patient complains that the dressing feels tight, the surgeon needs to be alerted immediately.

Generally, after surgery is completed, the patient is started on synthetic levothyroxine therapy to suppress TSH levels and establish a euthyroid (normal) state. Most patients do not have chemotherapy or radiotherapy because these modalities are usually ineffective with rapidly growing thyroid cancers. Chemotherapy is usually reserved as an adjuvant measure to halt the spread of metastasis; however, paclitaxel (Taxol) is currently being investigated as a treatment for anaplastic thyroid cancer.

Radioactive iodine (131I) may be used to destroy any remaining thyroid tissue not removed by surgery and to treat affected lymph nodes. For radioiodine therapy to be most effective, patients need to have high serum TSH levels; thus, an intentional hypothyroid condition is induced by stopping thyroid medications for 1 to 2 weeks. This temporary condition causes the pituitary gland to release more TSH.

Pharmacologic highlights

Medication or Drug Class	Dosage	Description	Rationale
Levothyroxine (Synthroid)	2.6 mcg/kg per day for 7–10 days	Synthetic T4 hormone	Suppresses TSH levels and establishes a euthyroid state postoperatively

Independent

The most important nursing interventions focus on teaching and prevention of complications. When you prepare patients before surgery, discuss not only the procedure and aftercare, but also the methods for postoperative communication such as a magic slate or a point board. Explain that the patient will be able to speak only rarely, will need to rest the voice for several days, and should expect to be hoarse. Answer all questions before surgery. After the procedure, monitor the patient’s ability to speak with each measurement of vital signs. Assess the patient’s voice tone and quality and compare it with the preoperative voice.

Maintaining a patent airway is the most important intervention. Maintain the bed in a high-Fowler position to decrease edema and swelling of the neck. To avoid pressure on the suture line, encourage the patient to avoid neck flexion and extension. Support the head and neck with pillows or sandbags; if the patient needs to be transferred from stretcher to bed, support the head and neck in good body alignment.

Before discharge, make sure the patient has a follow-up appointment for a postdischarge assessment. Make sure the patient has the financial resources to obtain all needed medications; some patients require thyroid supplements for the rest of their lives. Refer the patient or family to the American Cancer Society for additional information.

Evidence-Based Practice and Health Policy

Ward, M.H., Kilfoy, B.A., Weyer, P.J., Anderson, K.E., Folsom, A.R., & Cerhan, J.R. (2010). Nitrate intake and the risk of thyroid cancer and thyroid disease. Epidemiology, 21(3), 389–395.

Investigators conducted a cohort study among 21,977 women ages 55 to 69 and found that increased dietary nitrate intake was associated with an increased risk of thyroid cancer.
Compared with women in the lowest quartile of dietary nitrate intake (median, 12.4 mg/day), women in the highest quartile of dietary nitrate intake (median, 53.8 mg/day) were 2.85 times more likely to develop thyroid cancer (95% CI, 1 to 8.11; p = 0.046).
Higher dietary nitrate was associated with living in a town with a population of more than 10,000 people, more years of education, a higher level of recreational physical activity, and higher intakes of vitamin C and total calories.

Documentation guidelines

Physical findings: Patency of airway, breathing patterns, voice
Physical findings of incision: Wound edges, hematoma formation, bleeding, infection
Presence of complications: Thyrotoxicosis, hypocalcemia, hypothyroidism
Reaction to diagnosis of thyroid cancer
Understanding of and interest in cancer support groups

Discharge and home healthcare guidelines

To maintain a euthyroid state, teach the patient and family the symptoms of hypothyroidism for early detection of problems: weakness, fatigue, cold intolerance, weight gain, facial puffiness, periorbital edema, bradycardia, and hypothermia. Be sure the patient understands all medications, including the dosage, route, action, and adverse effects. Explain that the patient needs routine follow-up laboratory tests to check TSH and thyroxine (T4) levels. Be sure the patient knows when the first postoperative physician’s visit is scheduled. Explain any wound care and that the patient should expect to be hoarse for a week or so after the surgical procedure.