There are four types of thyroid cancer. One, anaplastic carcinoma, grows much faster than the others and is the most dangerous. Apart from genetics and previous exposure to radiation therapy on the neck, there are few risk factors for thyroid cancer. The cancers are sometimes treatable by surgery, radiation, or chemotherapy.
The thyroid gland is located in the neck below the larynx. It has two lobes connected by a bit of tissue called the isthmus. Its function is to take iodine from the diet and use it to make the hormones calcitonin and thyroid hormone.
Cells known as follicular cells make the thyroid hormone, and C cells make the calcitonin. A healthy thyroid is small and cannot be felt through the skin of the neck. Tumors may cause it to become lumpy.
Anaplastic carcinoma is the most lethal of all types of thyroid cancer, but it is also the most rare. It originally comes from the follicular cells. Of all the types of thyroid cancer, anaplastic carcinoma grows the quickest and is the hardest to treat. This type may also spread into the airway and affect the patient's ability to breathe.
Follicular carcinoma originates in the same cells as anaplastic carcinoma but does not grow as quickly. This type of cancer is more treatable than anaplastic carcinoma, especially if the patient is under 45 years of age or if the disease is in the early stages. It is more likely to return and spread after treatment than the other types of thyroid cancer.
Papillary thyroid cancer is responsible for most thyroid cancers. It also originates in the follicular cells but most often only in one lobe. This type of cancer tends to affect women who haven't yet reached menopause. The disease spreads slowly and has the highest survival rate of all the thyroid cancers.
Medullary thyroid cancer grows in the C cells of the gland. It also grows slowly. A genetic condition called multiple endocrine neoplasia type 2 (MEN2) can cause the tumor, but it can also occur in people without the MEN2 syndrome.
People of any age can develop one of these types of thyroid cancer. A family history of thyroid cancer or of the thyroid disease goiter raises the risk. Previous radiation therapy to the thyroid area, especially as a child, also increases the chances of thyroid cancer.
Surgical removal of the thyroid is usually part of a treatment regimen. A patient may also receive radiation therapy, or in some cases where the cancer has spread significantly, chemotherapy is an option. Thyroid hormone supplements need to be taken regularly after surgery.