About thyroid cancer

What should people know about thyroid cancer?

The thyroid is a butterfly-shaped gland in the neck. It is located below the Adam's apple and makes hormones. These hormones help control blood pressure, body temperature, the rate at which the heart beats and how fast food is converted into energy. Hormones from the thyroid gland also affect a child's growth and development. The thyroid uses iodine, a mineral found in foods, to make some of its hormones.

There are different types of thyroid cancers depending on the type of cell that is affected. These different types of thyroid cancer vary in how successfully they can be treated; the most common type (papillary carcinoma) grows slowly and is rarely fatal.

Each year, over 1,000 men and about 2,800 women are diagnosed with thyroid cancer in New York State. About 50 men and 70 women die from this disease in New York State each year.

Who gets thyroid cancer?

Thyroid cancer occurs about three times as often in women as in men. Women between the ages of 35 and 65 are at highest risk of getting thyroid cancer, followed by older people (both men and women). Thyroid cancer occurs more frequently in Whites and Asians than in Blacks.

What factors increase risk for developing thyroid cancer?

At this time, the causes of thyroid cancer are not well understood. However, scientists agree that certain factors increase a person's risk of developing this disease. These risk factors include:

  • Ionizing radiation. Exposure to high levels of ionizing radiation, particularly in childhood, has been linked with thyroid cancer. In the past, before doctors were aware of the dangers, ionizing radiation was used to treat conditions such as acne and swelling of the lymph nodes, tonsils and thymus gland. While these conditions are not now treated with radiation, people who received such treatments are at higher risk for developing thyroid cancer. In addition, ionizing radiation is currently used to treat children with cancers of the head and neck and certain types of leukemia. As more children survive these cancers, they are at higher risk of getting thyroid cancer later in life due to their radiation treatments.
  • Radioactive iodine. Exposure to radioactive iodine in childhood is also believed to be associated with thyroid cancer. Following the Chernobyl nuclear power plant explosion, there was an increase in thyroid cancer in children living in areas of eastern Europe affected by the disaster. Scientists believe this increase was due to radioactive iodine from the explosion. It is important to note, however, that radioactive substances released by nuclear power plants during routine operations have not been shown to increase risk for thyroid cancer.
  • Hereditary conditions and family history. Thyroid cancer is more common among people with certain inherited diseases including familial adenomatous polyposis, Gardner syndrome, Cowden disease, Carney complex (type 1), and Multiple endocrine neoplasia (MEN) syndrome. People with a history of familial medullary thyroid carcinoma or a family history of goiter are also at higher risk for getting thyroid cancer.

What other risk factors for thyroid cancer are scientists studying?

Many studies have been done on the effects of diet, particularly eating foods with iodine, on the risk of thyroid cancer. Several studies have shown a higher risk of thyroid cancer in places where there is very little iodine in the diet. Other studies suggest that the amount of iodine in the diet affects the type of thyroid cancer that develops.

Some studies have shown that having a non-cancerous thyroid condition or having a relative with a non-cancerous thyroid condition may be a risk factor for developing thyroid cancer. Scientists are also studying the possible relationship between obesity/overweight and increased risk of thyroid cancer.

Additional research is needed to determine the role, if any, these factors may have in the development of thyroid cancer.

Is the number of people with thyroid cancer increasing?

The incidence of thyroid cancer has been increasing nationally over the past 50 years. This is also true in New York State. Despite the increase in thyroid cancer incidence, mortality from the disease is not increasing.

Scientists are trying to determine the reasons for the increase in thyroid cancer. Some of the increase may be because health care providers are focusing more attention on thyroid problems. Another reason may be that doctors are better able to detect the disease through ultrasounds and other medical tests. The role of the increased use of medical procedures, such as CT scans, is also being examined.

What can I do to reduce my chances of getting thyroid cancer?

To help reduce the risk of getting thyroid cancer:

  • Discuss the risks and benefits of medical imaging, such as CT scans, with your health care provider to avoid unnecessary exposure to ionizing radiation. This is particularly important for children.
  • Ensure adequate iodine intake. Because table salt in the United States is supplemented with iodine, most people have adequate iodine in their diet.
  • Be aware of your family history and discuss any concerns with your health care provider.

How else can I reduce my risk for cancer?

  • Choose a healthy diet to achieve and maintain a healthy weight. Eat more vegetables, fruits and whole grains and eat less red and processed (e.g., bacon, sausage, luncheon meats, hot dogs) meats. These actions may reduce the risk of developing many types of cancer as well as other diseases.
  • Exercise regularly.
  • Do not smoke. If you currently smoke, quit. Avoid exposure to second hand smoke. For more information on quitting smoking, visit the NYS Smoker's Quitline at www.nysmokefree.com or call 1-866-NY-QUITS.
  • Talk with your health care provider about recommended cancer screenings.

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