Thyroid cancer begins in the thyroid gland, which is located in the front of the neck just below the larynx (voice box). The thyroid gland is part of the endocrine system, which regulates hormones in the body. The thyroid gland absorbs iodine from the bloodstream to produce thyroid hormone, which regulates a person’s metabolism.

Thyroid cancer begins when the cells in the thyroid begin to change, grow uncontrollably, and eventually form a tumor. There are two types of tumors: benign (noncancerous) and malignant (cancerous, meaning that it can spread to other parts of the body). Thyroid tumors can also be called nodules, and 90% of all thyroid nodules are benign.

A healthy thyroid gland is barely palpable (capable of being touched or felt). A normal gland has two lobes, one on each side of the windpipe, joined by a narrow strip of tissue called the isthmus. If a tumor develops in the thyroid, it is felt as a lump in the neck. A swollen or enlarged thyroid gland is called a goiter, which may be due to iodine deficiency. Most Americans receive enough iodine from salt, and a goiter under these circumstances is caused by other reasons.

The thyroid gland contains two types of cells: follicular cells, which are responsible for the production of thyroid hormone, and C cells, which make calcitonin, a hormone that participates in calcium metabolism.

There are four main types of thyroid cancer:

Papillary thyroid cancer. Papillary thyroid cancer develops from the follicular cells and grows slowly. It is usually found in one lobe; only 10% to 20% of papillary thyroid cancers appear in both lobes. Papillary thyroid cancer is a differentiated thyroid cancer, meaning that the tumor looks similar to normal thyroid tissue under a microscope.

Follicular thyroid cancer. Follicular thyroid cancer also develops from the follicular cells and usually grows slowly. Follicular thyroid cancer is also a differentiated thyroid cancer, but it is less common that papillary thyroid cancer.

These two types of cancer are very often curable, especially when found early and in people younger than 45. Together, papillary and follicular thyroid cancers make up 80% to 90% of thyroid cancers.

Medullary thyroid cancer (MTC). MTC develops in the C cells and is sometimes the result of a genetic syndrome called multiple endocrine neoplasia type 2 (MEN2). This tumor has very little, if any, similarity to normal thyroid tissue. MTC can often be controlled if it is diagnosed and treated before it spreads to other parts of the body. MTC accounts for 5% to 10% of thyroid cancers.

Anaplastic thyroid cancer. This rare and fast-growing, poorly differentiated thyroid cancer starts from differentiated thyroid cancer or a benign tumor of the gland. Anaplastic thyroid cancer can be subtyped into giant cell classifications. Because this type of cancer grows so quickly, it can be more difficult to treat successfully.

This section addresses these four main types of thyroid cancer. For lymphoma in the thyroid, please read Cancer.Net’s Guide to Lymphoma, Non-Hodgkin. For more information on sarcoma in the thyroid, review the Cancer.Net Guide to Sarcoma. For information on a tumor in the parathyroid gland, read Cancer.Net's Guide to Parathyroid Cancer.

Statistics

In 2009, an estimated 37,200 adults (10,000 men and 27,200 women) in the United States will be diagnosed with thyroid cancer. It is estimated that 1,630 deaths (690 men and 940 women) from this disease will occur this year. Thyroid cancer is the seventh most common cancer in women.

The five-year relative survival rate (the percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) for all stages of thyroid cancer is about 97%. The five-year relative survival rate of papillary and follicular thyroid cancers and MTC range from 97% to 100% for early-stage cancer and decrease with later-stage cancer (See Staging). Anaplastic thyroid cancer is associated with a much lower survival rate.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with thyroid cancer. Because the survival statistics are measured in five-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Statistics adapted from the American Cancer Society’s publication, Cancer Facts & Figures 2009.

Find out more about basic cancer terms used in this section.

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A risk factor is anything that increases a person’s chance of developing cancer. Some risk factors can be controlled, such as smoking, and some cannot be controlled, such as age and family history. Although risk factors can influence the development of cancer, most do not directly cause cancer. Some people with several risk factors never develop cancer, while others with no known risk factors do. However, knowing your risk factors and communicating them to your doctor may help you make more informed lifestyle and health-care choices.

The following factors can raise a person’s risk of developing thyroid cancer:

Genetics. Some types of thyroid cancer are associated with genetics.

• An abnormal RET oncogene, which can be passed from parent to child, may cause MTC. Not everyone with an altered RET oncogene will develop cancer. Blood tests and genetic tests can detect the gene. Once the altered RET oncogene is identified, a doctor may recommend surgery to remove the thyroid gland before cancer develops. People with MTC are encouraged to have genetic testing to determine if a mutation of the RET proto-oncogene is present. If so, genetic testing of siblings and children will be recommended.
  
  
• A family history of MTC increases a person’s risk. People with MEN2 syndrome are also at risk for developing other cancers.
  
  
• A family history of goiters increases the risk of developing papillary thyroid cancer.
  
  
• A family history of precancerous polyps in the colon increases the risk of developing papillary thyroid cancer.

Read more about the Genetics of Thyroid Cancer.

Radiation exposure. Exposure to moderate levels of radiation therapy may increase the risk of papillary and follicular thyroid cancers. Such sources of exposure include the following:

• Low-dose to moderate-dose x-ray treatments used before 1950 to treat children with acne, tonsillitis, and other head and neck problems may increase the risk of papillary and follicular thyroid cancers.
• People who have been treated with radiation therapy for Hodgkin lymphoma or other forms of lymphoma in the head and neck are at an increased risk for developing papillary or follicular thyroid cancer.
  
  
• One or more exposures to radioactive iodine (also called I-131), especially in childhood, may increase the risk of papillary and follicular thyroid cancers. Sources of I-131 include radioactive fallout from atomic weapons testing during the 1950s and 1960s, nuclear power plant accidents (for example, the 1986 Chernobyl nuclear power plant accident), and environmental releases from atomic weapon production plants.

Diet low in iodine. Iodine is needed for normal thyroid functioning. In the United States, iodine is added to salt to help prevent thyroid problems.

Gender. Women are two to three times more likely to develop thyroid cancer than men.

Age. Thyroid cancer can occur at any age. Anaplastic thyroid cancer is usually diagnosed after age 60. Older infants (10 months and older) and adolescents can develop MTC, especially if they carry the RET proto-oncogene mutation (see above).

Race. White people are more likely to develop thyroid cancer than black people.

People with thyroid cancer often experience the following symptoms. Sometimes, people with thyroid cancer do not show any of these symptoms. Or, these symptoms may be similar to those of other medical conditions. If you are concerned about a symptom on this list, please talk with your doctor.

• A lump in the front of the neck, near the Adam's apple
  
  
• Hoarseness
  
  
• Swollen glands in the neck
  
  
• Difficulty swallowing
  
  
• Difficulty breathing
  
  
• Pain in the throat or neck
  
  
• A cough that persists and is not caused by a cold

These symptoms may be caused by thyroid cancer; other thyroid problems, such as a goiter; or a condition not related to the thyroid, such as an infection. Talk with your doctor for more information.

Doctors use many tests to diagnose cancer and determine if it has metastasized (spread). Some tests may also determine which treatments may be the most effective. For most types of cancer, a biopsy is the only way to make a definitive diagnosis of cancer. If a biopsy is not possible, the doctor may suggest other tests that will help make a diagnosis. Imaging tests may be used to find out whether the cancer has metastasized. Your doctor may consider these factors when choosing a diagnostic test:

• Age and medical condition
• The type of cancer suspected
• Severity of symptoms
• Previous test results

The following tests may be used to diagnose thyroid cancer:

Physical examination. The doctor will feel the neck, thyroid, throat, and lymph nodes (the tiny, bean-shaped organs that help fight infection) in the neck for unusual growths or swelling. If surgery is recommended, the larynx may be examined at the same time with a laryngoscope (thin, flexible tube with a light).

Blood tests. The doctor may use a blood test to check the level of thyroid-stimulating hormone (TSH). A measurement of thyroid hormone levels and antithyroid antibodies may be done as well. If MTC is a possibility, the doctor will order a test to check for high calcitonin levels and a blood test to detect the presence of RET proto-oncogenes (Risk Factors). The search for RET proto-oncogenes is often recommended if there is a family history of MTC.

Ultrasound. An ultrasound uses sound waves to create a picture of the internal organs. An ultrasound wand or probe is guided over the skin of the neck area. High-frequency sound waves create a pattern of echoes that show the doctor the thyroid gland size and specific information about any nodules, including whether they are solid or cysts (fluid-filled sacs).

Biopsy. A biopsy is the removal of a small amount of tissue for examination under a microscope. The way to determine whether a nodule is malignant or benign is through a biopsy. During this procedure, the doctor removes cells from the nodule that are then examined by a cytopathologist (a doctor who specializes in analyzing cells and tissue) to determine if cancer is present. A biopsy for thyroid nodules will be done one of two ways:

• Fine needle aspiration. This procedure is usually performed in a doctor’s office or clinic. It is an important diagnostic step to determine if a thyroid nodule is benign or malignant. A local anesthetic may be injected into the skin to numb the area before the biopsy. The doctor inserts a thin needle into the nodule and removes cells and some fluid. The procedure may be repeated two or three times to obtain samples from different areas of the nodule. The report done by the pathologist (a doctor who specializes in interpreting laboratory tests and evaluating cells, tissues, and organs to diagnose disease) can be positive (meaning there are cancerous cells), negative (meaning there are no cancerous cells), or undetermined.
  
  
• Surgical biopsy. If the needle aspiration biopsy is not clear, the doctor may suggest a biopsy in which the nodule and possibly the affected lobe of the thyroid will be removed. This procedure is usually done under general anesthesia and on an inpatient or outpatient basis.

Radionuclide scanning. This test, also called a full body scan or a radioactive iodine (RAI) scan, is used most often to learn more about a thyroid nodule. In this test, the patient swallows a small, harmless amount of radioactive iodine, which allows the doctor to see differences between thyroid cells and other body structures.

To learn more about what to expect during common diagnostic tests, read Cancer.Net: Tests and Procedures.

To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: Newly Diagnosed.

Staging is a way of describing a cancer, such as where it is located, if or where it has spread, and if it is affecting the functions of other organs in the body. Doctors use diagnostic tests to determine the cancer’s stage, so staging may not be complete until all of the tests are finished. Knowing the stage helps the doctor to decide what kind of treatment is best and can help predict a patient's prognosis (chance of recovery). There are different stage descriptions for different types of cancer.

One tool that doctors use to describe the stage is the TNM system. This system uses three criteria to judge the stage of the cancer: the tumor itself, the lymph nodes around the tumor, and if the tumor has spread to other parts of the body. The results are combined to determine the stage of cancer for each person. There are five stages: stage 0 (zero) and stages I through IV (one through four). The stage provides a common way of describing the cancer, so doctors can work together to plan the best treatments.

TNM is an abbreviation for tumor (T), node (N), and metastasis (M). Doctors look at these three factors to determine the stage of cancer:

• How large is the primary tumor and where is it located? (Tumor, T)
  
  
• Has the tumor spread to the lymph nodes? (Node, N)
  
  
• Has the cancer metastasized to other parts of the body? (Metastasis, M)

In addition to the TNM system, papillary and follicular thyroid cancers are also staged by the age of the patient.

Tumor. Using the TNM system, the letter “T” plus a letter or number (0 to 4) is used to describe the size and location of the tumor. Some stages are also divided into smaller groups that help describe the tumor in even more detail. When describing “T” in thyroid cancer, doctors may subdivide the general categories by adding the letter “a” to indicate a solitary (single) tumor or “b” to indicate multifocal (more than one) tumors. Specific tumor stage information is listed below.

TX: The primary tumor cannot be evaluated.

T0: There is no evidence of a tumor.

T1: The tumor is 1 centimeter (cm) or smaller at its greatest dimension and limited to the thyroid.

T2: The tumor is at least 1 cm, but it is not larger than 4 cm and is limited to the thyroid.

T3: The tumor is larger than 4 cm, but the tumor does not extend beyond the thyroid gland.

T4: The tumor is any size and has extended beyond the thyroid.

Node. The “N” in the TNM staging system stands for lymph nodes. There are many regional lymph nodes located in the head and neck area, and careful assessment of lymph nodes is an important part of staging thyroid cancer. Lymph nodes in other parts of the body are called distant lymph nodes.

NX: The regional lymph nodes cannot be evaluated.

N0: There is no evidence of cancer in the regional lymph nodes.

N1: Cancer has spread to the lymph nodes.

N1a: Cancer has spread to the ipsilateral cervical lymph nodes (lymph nodes in the neck on the same side as the tumor).

N1b: Cancer has spread to the bilateral cervical (lymph nodes on both sides of the neck), the contralateral cervical (the opposite side of the tumor), the midline cervical (the middle of the neck), or the mediastinal (the chest) lymph nodes.

Distant metastasis. The “M” in the TNM system indicates whether cancer has spread to other parts of the body.

MX: Distant metastasis cannot be evaluated.

M0: Cancer has not spread to other parts of the body.

M1: Cancer has spread to other parts of the body.

Cancer stage grouping

Doctors assign the stage of the cancer by combining the T, N, and M classifications. For thyroid cancer, this staging system differs by tumor type and by the age of the patient.

Papillary or follicular thyroid tumors, in a person younger than 45

Stage I: This stage describes a tumor (any T) with no spread to lymph nodes (N0) and no distant metastasis (M0).

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Stage II: This stage describes a tumor (any T) with any metastasis (M1) regardless of whether it has spread to the lymph nodes (any N).

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Papillary or follicular thyroid tumors, in a person 45 and older

Stage I: This stage describes any small tumor (T1) with no spread to lymph nodes (N0) and no metastasis (M0).

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Stage II: This stage describes any larger, noninvasive tumor (T2, T3) with no spread to lymph nodes (N0) and no metastasis (M0).

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Stage III: This stage describes any invasive tumor (T4) with no spread to lymph nodes (N0) and no metastasis (M0), or any tumor (any T) with spread to lymph nodes (N1).

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Stage IV: This stage describes all tumors (any T, any N) when there is evidence of metastasis (M1).

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Medullary thyroid tumors

Stage I: This stage describes a small tumor (T1) with no spread to lymph nodes (N0) and no distant metastasis (M0).

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Stage II: This stage describes any tumor (any T) with no spread to lymph nodes (N0) and no metastasis (M0).

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Stage III: This stage describes any tumor (any T) that has spread to lymph nodes (N1) but has not metastasized (M0).

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Stage IV: This stage is used when there is evidence of metastasis (any T, any N, M1).

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Anaplastic thyroid tumors

Stage IV: All anaplastic thyroid tumors are classified as stage IV, regardless of tumor size, location, or metastasis.

Recurrent: Recurrent cancer is cancer that comes back after treatment.

Used with permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Sixth Edition (2002) published by Springer-Verlag New York, www.springer-ny.com.

The treatment of thyroid cancer depends on the size and location of the tumor, the type of thyroid cancer, whether the cancer has spread, and the person’s overall health. In many cases, a team of doctors will work with the patient to determine the best treatment plan, including a surgeon, endocrinologist (a doctor specializing in problems with glands and the endocrine system), medical oncologist, and radiation oncologist.

This section outlines treatments that are the standard of care (the best treatments available) for this specific type of cancer. Patients are also encouraged to consider clinical trials as a treatment option when making treatment plan decisions. A clinical trial is a research study to test a new treatment to prove it is safe, effective, and possibly better than standard treatment. Your doctor can help you review all treatment options. For more information, visit the Clinical Trials section.

Cancer treatment is often selected based on guidelines recommended by panels of expert physicians. Although most thyroid cancers are curable, there can be different opinions in how to treat thyroid cancer, particularly in which combination of treatments to use. Patients are encouraged to seek a second opinion before starting treatment because they should be comfortable with the treatment plan they choose and should ask about clinical trials.

Thyroid cancer is treated by one or a combination of treatments, including surgery, radioactive iodine, hormone treatment, external-beam radiation therapy, and/or chemotherapy. The main treatment options are described below, followed by an outline of treatment options by stage.

Surgery

Surgery is the main treatment for most thyroid cancers. Depending on the size of the nodule, the surgeon will perform a total thyroidectomy (surgery to remove the entire thyroid gland), a near-total thyroidectomy (surgery to remove the thyroid gland except for a small part), or a lobectomy (surgery to remove the lobe with the cancerous nodule). Total or near-total thyroidectomies are the most common operations for thyroid cancer; lobectomies are performed on some patients with papillary or follicular thyroid cancer. If there is evidence or risk of spread of cancer to the lymph nodes in the neck, the surgeon may also perform a neck dissection (surgery to remove the lymph nodes in the neck).

Complications of surgery may include damage to the parathyroid glands (which help regulate blood calcium levels) and excessive bleeding or wound infections. If the nerves to the larynx are damaged during surgery, this may cause temporary or permanent hoarseness or a “breathy” voice.

Without the thyroid gland, the body stops producing thyroid hormone, which is essential to a body’s functioning. Hormone replacement (see below), usually given by a daily pill, is the best solution. The patient may also have to take vitamin D and calcium supplements if the parathyroid gland function is impaired after surgery.

Hormone treatment

Patients who are treated for papillary, follicular, and medullary thyroid cancers by surgery require thyroid hormone therapy. In addition to replacing the hormone that is needed by the body, the thyroid hormone medication will slow down the growth of any remaining differentiated cancer cells, an important double purpose.

Thyroid hormone replacement is levothyroxine (Levothroid, Levoxyl, Synthroid, Unithroid). Levothyroxine typically comes as a pill that should be taken daily, at the same time each day. Thyroid pills have few side effects. Occasionally, some patients develop a rash or lose some hair during the first months of treatment. The doctor will monitor the patient’s thyroid hormone levels through regular blood tests. Hyperthyroidism (too much hormone) may cause weight loss, chest pain, rapid heart rate or arrhythmias (irregular heartbeat), cramps, and diarrhea; patients may also feel hot and sweaty. Hypothyroidism (too little hormone) may cause fatigue, weight gain, and dry skin and hair; patients may also feel cold. The amount of thyroid hormone required is different for every patient and tumor type, and it can change as a person ages.

Radioactive iodine (radioiodine) therapy

The thyroid absorbs almost all iodine that enters a body. Therefore, radioactive iodine (also called I-131) is given as a way to find and destroy thyroid cells not removed by surgery and those that have spread beyond the thyroid.

Not all patients require this treatment. Patients with medullary or anaplastic thyroid cancer are not treated with I-131.

I-131 therapy is given in either liquid or pill form. Patients receiving I-131 to kill cancer cells may or may not be hospitalized for two to three days, depending on several factors including the dose given.

Patients are encouraged to drink fluids to help the I-131 pass quickly through the body. Within a few days, most of the radiation is gone. Talk with your doctor about ways to limit radiation exposure to other people, including children, who may be around you during this treatment and the days following it.

In preparation for radioactive iodine treatment after surgery, patients are usually asked to avoid an iodine-rich diet for two to three weeks beforehand. In addition to the low-iodine diet, patients will be asked to either stop taking thyroid hormone replacement pills temporarily or will receive injections of recombinant TSH (Thyrogen) while taking the hormone replacement.

It is important to discuss the possible short-term and long-term effects of I-131 therapy with your doctor. On the first day of treatment, patients may experience nausea and vomiting. In certain circumstances, pain and swelling can occur in the areas where the radioactive iodine is collected. Because iodine is concentrated in salivary gland tissue, patients may experience swelling of the salivary glands; this may result in xerostomia (dry mouth).

Large or cumulative doses of radioactive iodine may cause infertility, especially in men. It is recommended that women avoid pregnancy for at least one year after radioactive iodine treatment. Occasionally, patients may require repeated radioactive treatments over time. However, there is a maximum total dose of radioactive iodine allowed over time, and once reached, this may prevent further use of this treatment.

Epidemiologic studies (studies that determine the cause of cancer in large groups of people) have shown that repeated high-dose radioactive treatment can cause leukemia and occasionally urinary bladder carcinoma.

External-beam radiation therapy

Radiation uses high-energy x-rays to kill cells. The most common type of radiation treatment is called external-beam radiation therapy, which is radiation given from a machine outside the body. Radiation therapy is usually given as outpatient therapy five days a week for about five to six weeks either in a hospital or clinic.

For thyroid cancer, radiation therapy is used only in certain circumstances, typically when advanced thyroid cancer has not responded to radioiodine therapy. Radiation therapy is usually given after surgery, and treatment is concentrated on a specific area, only affecting cancer cells at that site.

Side effects depend on the treatment dosage and area and may include redness of the skin, odynophagia (painful swallowing), cough, occasional hoarseness, nausea, and fatigue. Most side effects go away soon after treatment is finished.

Chemotherapy

Chemotherapy is the use of drugs to kill cancer cells and is sometimes used to treat thyroid cancer. Systemic chemotherapy is delivered through the bloodstream, targeting cancer cells throughout the body. The goal of chemotherapy can be to destroy cancer remaining after surgery, slow the tumor’s growth, or reduce symptoms.

The side effects of chemotherapy depend on the individual and the dose used. The side effects of chemotherapy depend on the individual and the dose used but can include fatigue, risk of infection, nausea and vomiting, loss of appetite, and diarrhea. These side effects usually go away once treatment is finished.

At this time, the use of systemic chemotherapy for the treatment of thyroid cancer is determined on an individual basis and is most often given as part of a clinical trial (research study). With new knowledge in the molecular abnormalities of cancer cells, scientists are developing therapies that specifically target such abnormalities. In turn, the cancer therapy can be more specific. See the Current Research section for more information.

The medications used to treat cancer are continually being evaluated. Talking with your doctor is often the best way to learn about the medications you've been prescribed, their purpose, and their potential side effects or interactions with other medications. Learn more about your prescriptions through Cancer.Net’s Drug Information Resources, which provides links to searchable drug databases.

Treatment options by stage

If the thyroid cancer is only within the tissues of the neck, both in the thyroid gland and in the lymph nodes, surgery will typically be the first treatment. Patients with more advanced disease may be treated with surgery as well, but other treatments may be done first.

Stage I: Surgery; hormone therapy; possible radioactive iodine therapy after surgery

Stage II: Surgery; hormone therapy; possible radioactive iodine therapy after surgery

Stage III: Surgery; hormone therapy; possible radioactive iodine therapy or external-beam radiation therapy after surgery

Stage IV (advanced): Stage IV thyroid cancer is the most advanced stage of the disease. The cancer has spread beyond the thyroid to the lymph nodes and other organs, such as the bones or lungs.

Symptoms of advanced thyroid cancer are similar to those present when the disease was first diagnosed:

• A lump in the front of the neck, near the Adam’s apple
  
  
• Hoarseness
  
  
• Swollen glands, especially in the neck
  
  
• Difficulty swallowing
  
  
• Difficulty breathing
  
  
• Pain in the throat or neck
  
  
• A cough that persists and is not caused by a cold
  
  
• Bone pain, specifically when metastases develop in the skeleton

Treatment for advanced thyroid cancer may include a combination of surgery, hormone therapy, radioactive iodine therapy, external-beam radiation therapy, and chemotherapy. Radiation therapy may also be used to reduce pain and other problems. Patients with advanced thyroid cancer may consider participating in clinical trials.

Recurrent thyroid cancer

Recurrent thyroid cancer is cancer that comes back after treatment. Treatment for recurrent cancer will depend on the type of treatment given previously, the type of thyroid cancer, and where the cancer recurs. A combination of treatments will likely include: external-beam radiation therapy, chemotherapy, surgery, radioactive iodine treatment, hormone treatment, and clinical trials. In certain instances, a positron emission tomography (PET) scan may be used to determine the extent of the cancer. In a PET scan, radioactive sugar molecules are injected into the body. Cancer cells absorb sugar more quickly than normal cells, so they light up on the PET scan.

To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: During Treatment.

Doctors and scientists are always looking for better ways to treat patients with thyroid cancer. A clinical trial is a way to test a new treatment in order to prove that it is safe, effective, and possibly better than a standard treatment. Patients who participate in clinical trials are among the first to receive new treatments, such as new chemotherapeutic drugs, before they are widely available. However, there is no guarantee that the new treatment will be safe, effective, or better than a standard treatment.

Patients decide to participate in clinical trials for many reasons. For some patients, a clinical trial is the best treatment option available. Because standard treatments are not perfect, patients are often willing to face the added uncertainty of a clinical trial in the hope of a better result. Other patients volunteer for clinical trials because they know that finding new drugs and other therapies is the only way to make progress in treating thyroid cancer. Even if they do not benefit directly from the clinical trial, their participation may benefit future patients with thyroid cancer.

To join a clinical trial, patients must complete a learning process known as informed consent. During informed consent, the doctor should list all of the patient's options, so the person understands how the new treatment differs from the standard treatment. The doctor must also list all of the risks of the new treatment, which may or may not be different than the risks of standard treatment. Finally, the doctor must explain what will be required of each patient in order to participate in the clinical trial, including the number of doctor visits, tests, and the schedule of treatment. Learn more about clinical trials, including patient safety, phases of a clinical trial, deciding to participate in a clinical trial, questions to ask the research team, and links to find cancer clinical trials.

Cancer and its treatment can cause a variety of side effects. However, doctors have made major strides in recent years in reducing pain, nausea and vomiting, and other physical side effects of cancer treatments. Many treatments used today are less intensive but as effective as treatments used in the past. Doctors also have many ways to provide relief to patients when such side effects do occur.

Fear of treatment side effects is common after a diagnosis of cancer, but it may be helpful to know that preventing and controlling side effects is a major focus of your health-care team. Before treatment begins, talk with your doctor about possible side effects of the specific treatments you will be receiving. The specific side effects that can occur depend on a variety of factors, including the type of cancer, its location, the individual treatment plan (including the length and dosage of treatment), and the person’s overall health.

Ask your doctor which side effects are most likely to happen (and which are not), when side effects are likely to occur, and how they will be addressed by the health-care team if they do happen. Also, be sure to communicate with the doctor about side effects you experience during and after treatment. For more information on the most common side effects of cancer and different treatments, along with ways to prevent or control them, visit Cancer.Net’s section on Managing Side Effects, based on ASCO’s curriculum.

In addition to physical side effects, there may be psychosocial (emotional and social) effects as well. Learn more about the importance of addressing these needs in Cancer.Net’s section on Caring for the Whole Patient.

After treatment for thyroid cancer ends, talk with your doctor about developing a follow-up care plan. This plan may include physical examinations and/or medical tests on a regular basis to monitor your recovery in the coming months and years. People treated for thyroid cancer are encouraged to receive routine follow-up care over the course of their lifetimes.

People treated for thyroid cancer are typically asked to return to the doctor’s office every six months to a year. At a follow-up care visit, the doctor will conduct a physical examination and blood tests to determine the level of thyroid-stimulating hormone (TSH) suppression and to test for thyroglobulin, the substance that stores hormones in the thyroid gland. If the thyroid gland has been removed, there should be little or no thyroglobulin in the blood. An elevated level of thyroglobulin may indicate recurrent cancer. Other blood tests may be done depending on the specific type of thyroid cancer treated. Blood tests also help the doctor determine the correct dosage of the patient’s thyroid replacement medication (if needed), which may be adjusted over time.

Other follow-up tests may include a chest x-ray, an ultrasound of the neck, a full-body scan (a test that detects thyroid cancer cells anywhere in the body), or other imaging tests. If the doctor recommends a procedure that uses radioactive iodine (I-131), patients may have to stop taking their thyroid medication up to six weeks and/or may be asked to follow a low-iodine diet for up to two weeks before having the test.

Based on the type of treatment received, the doctor will determine what examinations and tests are needed to check for long-term side effects, including the possibility of secondary cancers. As explained in the Treatment section, this is particularly important for people who have received I-131 treatment. And, young women who are treated for papillary or follicular thyroid cancer have a higher risk of developing breast cancer in the future and should talk with their doctor about appropriate breast cancer screening recommendations.

People recovering from thyroid cancer are encouraged to follow established guidelines for good health, such as maintaining a healthy weight, not smoking, eating a balanced diet, and having recommended cancer screening tests. Talk with your doctor to develop a plan that is best for your needs.

Moderate exercise can help you rebuild your strength and energy level. Talk with your doctor about helping you create an appropriate exercise plan based upon your needs, physical abilities, and fitness level. Learn more about Healthy Living After Cancer.

To learn about the terms used in this section, read the Cancer.Net Feature: Cancer Terms to Know: After Treatment.

Research for thyroid cancer is ongoing. The following advances may still be under investigation in clinical trials and may not be approved or available at this current time. Always discuss all diagnostic and treatment options with your doctor.

• A new surgical procedure, called minimally invasive video-assisted thyroid surgery, is being developed. Currently, this type of surgery has very limited availability, and only a few surgical centers have the expertise to perform this procedure.
  
  
• New therapies for thyroid cancer include experimental combinations of chemotherapy and other treatments. Radio-labeled antibodies (an antibody made in the laboratory attached to a radioactive substance) are being tested for MTC.
  
  
• Also for MTC, there is a clinical trial studying the drug vandetanib (zd6474, Zactima) for children with advanced hereditary MTC.
  
  
• For anaplastic thyroid cancer, a clinical trial is studying combination chemotherapy, comparing the results of either (carboplatin [Paraplatin] and paclitaxel [Taxol]) alone, or with an experimental drug, combretastatin A4 phosphate (CA4P, Zybrestat).
  
  
• For advanced thyroid cancer that does not respond to surgery and/or I-131 treatment, clinical trials are studying axitinib and other vascular endothelial growth factor (VEGF) inhibitors, which may block the formation of new blood vessels that are necessary for tumor growth. Another VEGF inhibitor, AMG 706 or motesanib diphosphate, was shown in a phase II clinical trial to shrink tumors or delay the growth of them in some people with advanced thyroid cancer. Also, in patients whose tumors showed a genetic mutation known as BRAF V600E, the tumors responded better to the investigational drug.
  
  
• Targeted therapies guided at specific molecular alterations of the cancer can make treatment more specific and potentially less toxic to the patient.
  
  
• Investigations are underway to fine-tune diagnosis and predict treatment outcomes based on the molecular biology (the study of the structure and function of cells at the molecular level) of the tumor.
  
  
• The genetic testing and the refinement of RET oncogenes (see Risk Factors) is an ongoing area of active research that will improve selection of treatment and give more precise prognosis.

Regular communication with your doctor is important in making informed decisions about your health care. Consider asking the following questions of your doctor:

• What type of thyroid cancer do I have?
  
  
• What is the stage of the cancer? What does this mean?
  
  
• What are my treatment options?
  
  
• What clinical trials are open to me?
  
  
• What treatment plan do you recommend? Why?
  
  
• Where can I get a second opinion?
  
  
• Is surgery recommended? If so, how much of my thyroid gland will be removed? Will lymph nodes be removed as well?
  
  
• Do I need other tests, such as an ultrasound, before surgery to determine the extent of the cancer?
  
  
• Is radioactive iodine treatment recommended? Why or why not? If so, can you describe this procedure to me?
  
  
• What are the short-term and long-term side effects of my treatment?
  
  
• If MTC is diagnosed, do I need a genetic test? Why or why not? Should family members be tested?
  
  
• What are the chances the cancer will recur?
  
  
• What is the recommended follow-up care plan after treatment is over?
  
  
• What support services are available to me? To my family?

ThyCa: Thyroid Cancer Survivors' Association, Inc.
P.O. Box 1545
New York, NY  10159-1545
Phone: 877-588-7904
www.thyca.org

American Thyroid Association
6066 Leesburg Pike, Suite 550
Falls Church, VA  22041
Toll Free: 800-THYROID (847643)
Phone: 703-998-8890
www.thyroid.org

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