Thyroid cancer numbers in U.S. increasing

Thyroid cancer occurs in the cells of the thyroid — a butterfly-shaped gland located at the base of the neck below the adam’s apple.

The gland produces hormones that regulate heart rate, blood pressure, body temperature and weight.

Thyroid cancer isn’t common in the U.S. but rates seem to be increasing. Doctors think it’s because new technology is helping them find small cancers that may not have been found in the past.

Most cases of thyroid cancer can be cured with treatment.

Thyroid cancer typically doesn’t cause any signs or symptoms early in the disease. As thyroid cancer grows, it may cause a lump that can be felt; voice changes; difficulty swallowing; pain in the neck and throat, and swollen neck lymph nodes.

Thyroid cancer occurs when cells in the thyroid undergo mutations that allow cells to grow and multiply rapidly. The cells also lose the ability to die, as normal cells would. The accumulating abnormal thyroid cells form a tumor. The abnormal cells can invade nearby tissue and can spread throughout the body.

The type of thyroid cancer you have determines treatment and prognosis.

There are many different types including papillary thyroid cancer; follicular thyroid cancer; medullary thyroid cancer; anaplastic thyroid cancer, and thyroid lymphoma.

Risk factors

Thyroid cancer occurs more often in women than in men and exposure to high levels of radiation increase the chance of the disease. Examples of high levels of radiation include those that come from radiation treatment to the head and neck and from fallout from such sources as nuclear power plant accidents or weapons testing.

Some genetic syndromes increase the risk of thyroid cancer including familial medullary thyroid cancer, multiple endocrine neoplasia and familial adenomatous polyposis.

Despite treatment, thyroid cancer can return, even if someone has had their thyroid removed. This could happen if microscopic cancer cells spread beyond the thyroid before it’s removed.

Thyroid cancer recurrence most often occurs in the first five years after surgery, but it can recur decades after your initial thyroid cancer treatment.

Thyroid cancer may recur in lymph nodes; small pieces of thyroid tissue left behind during surgery, and other areas of the body.

If it returns, the disease can be treated.

During an exam, the doctor will look for physical changes in the thyroid and ask about risk factors, such as excessive exposure to radiation and a family history of thyroid tumors.

Blood tests help determine if the thyroid gland is functioning normally and the doctor may event remove a sample of the thyroid.

The physican may order imaging tests to help determine whether your cancer has spread.

Some people with medullary thyroid cancer may have genetic changes that can be associated with other endocrine cancers.

Treatments

Your thyroid cancer treatment options depend on the type and stage of the cancer. Most cases of thyroid cancer can be cured with treatment.

Most people with thyroid cancer undergo surgery to remove all or most of the thyroid.

The surgeon may remove all or most of the thyroid or only a small portion and also the lymph nodes in the neck.

Thyroid surgery carries a risk of bleeding and infection. Damage can also occur to your parathyroid glands during surgery, which can lead to low calcium levels. There’s also a risk of accidental damage to the nerves connected to your vocal cords, which can cause vocal cord paralysis, hoarseness, soft voice or difficulty breathing.

After surgery patients must take the thyroid hormone medication levothyroxine for life. The medication supplies the missing hormone the thyroid would normally produce, and it suppresses the production of thyroid-stimulating hormone (TSH) from the pituitary gland. High TSH levels could conceivably stimulate any remaining cancer cells to grow.

Radioactive iodine treatment uses large doses of a form of iodine that’s radioactive.

Radioactive iodine treatment is often used after thyroidectomy to destroy any remaining healthy thyroid tissue, as well as microscopic areas of thyroid cancer that weren’t removed during surgery. Radioactive iodine treatment may also be used to treat thyroid cancer that recurs after treatment or that spreads to other areas of the body.

Side effects can include nausea, dry mouth and eyes, altered sense of taste or smell and/or pain if thyroid cancer cells have spread.

Most of the radioactive iodine leaves the body with urination in a few days.

Radiation can also be given externally with a machine that aims high-energy beams at precise points on your body. This treatment is typically administered a few minutes at a time, five days a week, for about five weeks.

External beam radiation therapy may be an option if you can’t undergo surgery and a person’s cancer continues to grow after radioactive iodine treatment. It may also be used to slow the growth of cancer that has spread to the bones.

Chemotherapy is a drug treatment that uses chemicals to kill cancer cells typically given as an infusion through a vein. Chemotherapy is not commonly used in the treatment of thyroid cancer but it may benefit some people who don’t respond to other therapies.

Alcohol ablation involves injecting small thyroid cancers with alcohol using imaging such as ultrasound to ensure precise placement of the injection. This treatment is helpful for treating cancer that occurs in areas that aren’t easily accessible during surgery.

Targeted drug therapy uses medications that attack specific vulnerabilities in your cancer cells. These drugs target the signals that tell cancer cells to grow and divide.

Prevention

Doctors aren’t sure what causes most cases of thyroid cancer, so there’s no way to prevent it in people who have an average risk of the disease.

Adults and children with an inherited gene mutation that increases the risk of medullary thyroid cancer, however, are often advised to have thyroid surgery to prevent cancer.

Fallout from an accident at a nuclear power plant could cause thyroid cancer in those living nearby. If you live within 10 miles of a nuclear power plant in the U.S., you may be eligible to receive a medication that blocks the effects of radiation on the thyroid.

If an emergency were to occur, you and your family could take the potassium iodide tablets to help prevent thyroid cancer. Contact your state or local emergency management department for more information.

Mayo Clinic Staff