Thyroid cancer is a malignancy (cancerous growth) of the thyroid gland.
Alternative Names: Tumor - thyroid; Cancer - thyroid
Causes, incidence, and risk factors:
Thyroid cancer can occur in all age groups. People who have had radiation therapy to the neck are at higher risk. This therapy was commonly used in the 1950s to treat enlarged thymus glands, adenoids and tonsils, and skin disorders. People who received radiation therapy as children have a higher incidence of thyroid cancer.
Other risk factors are a family history of thyroid cancer and chronic goiter. The disease affects 1 in 1,000 people.
There are several types of thyroid cancer:
Note: Symptoms may vary depending on the type of thyroid cancer
Signs and tests:
A physical examination can reveal a thyroid mass or nodule (usually in the lower part of the front of the neck) or enlarged lymph nodes in the neck.
Tests that indicate thyroid cancer:
This disease may also alter the results of the following tests:
Treatment varies depending on the type of tumor.
Surgery is usually the treatment of choice, with usually the entire thyroid gland removed. If the physician suspects that the cancer has spread to lymph nodes in the neck, these will also be removed during surgery.
Radiation therapy with radioactive iodine is often used with or without surgery. Radiation therapy with beam radiation can also be used.
After treatment, patients need to take thyroid hormone to replace what their glands used to make. The dose is usually a little higher than what the body needs, which helps keep the cancer from coming back.
If the cancer does not respond to surgery or radiation and has spread to other parts of the body, chemotherapy may be used, but this is only effective for about a third of patients.
The stress of the illness can often be eased by joining a support group of people who share common experiences and problems. See cancer - support group.
Anaplastic carcinoma has the worst prognosis (probable outcome). One variety of this cancer, the giant cell type, carries an expected life span of less than 6 months after diagnosis.
Follicular carcinomas are often fast growing and may invade other tissues, but the probable outcome is still good -- over 90% of patients are cured. The outcome with medullary carcinoma varies. Women under 40 years old have a better chance of a good outcome. The cure rate is 40-50%.
Papillary carcinomas are usually slower growing. Most people are cured (over 95%) and have a normal life expectancy.
Calling your health care provider:
Call your health care provider if you notice a nodule or mass in your neck.
Also call if symptoms worsen during treatment.
There is no known prevention. Awareness of risk (such as previous radiation therapy) can allow earlier diagnosis and treatment.