What is thyroid cancer?

Understanding Thyroid Cancer

The thyroid is a butterfly-shaped gland in the throat. It makes hormones out of iodine and knows how much to release because of the pituitary gland. Once released, the hormones are then sent throughout the body to control your metabolism.

Your metabolism is more than just how fast your burn calories—it’s how fast your whole body works, from the brain to the heart, to the liver.  When thyroid cells become abnormal, they no longer have the ability to die off, like normally functioning ones do. They accumulate until nodules (small, mostly tissue-filled lumps) form on the gland. While they are generally benign (non-cancerous), this build up of abnormal cell growth can cause thyroid cancer.

Symptoms of Thyroid Cancer 

Three-quarters of the population will wind up with a nodule forming on the thyroid, and the chances of developing one increase with age. However, these turn out to be malignant less than 1% of the time. Thyroid cancer may not cause any issues for many years, but once it becomes noticeable, it is often diagnosed quickly, which increases the chances of successful treatment. Signs include a sore throat, hoarse voice, and swollen lymph nodes. You may notice that your neck is swollen, you may have trouble swallowing or breathing, and you cough frequently for no reason.

Diagnosis of Thyroid Cancer

If your doctor suspects thyroid cancer after a physical exam, they may run blood tests to see if the thyroid gland is functioning like it should. If levels come back abnormal, a biopsy will be performed. For this, an extremely thin needle is inserted through the skin and into the nodule with the help of an ultrasound. Through the needle, a small sample of tissue is removed, which is then examined in a laboratory for abnormal cells. Your doctor may perform a computerized tomography (CT) scan, ultrasound, or positron emission tomography to see if the cancerous cells have spread elsewhere in the body.   

Medical experts categorize thyroid cancer into four categories: 

  • Papillary: More than three-quarters of all thyroid cancer are papillary, which is good, since it has the highest cure rate. It may spread to the lymph nodes but rarely moves elsewhere.
  • Follicular: This is the second most common type, and like most thyroid cancers, it occurs more often in females. It too is generally curable, but becomes less so with age. It is associated with radiation exposure.  It tends to spread into the veins and arteries.
  • Medullary: Medullary thyroid cancer is less common but has a much worse prognosis than other forms. It also arises from a different part of the thyroid than papillary and follicular cancer. It can spread, not only to the lymph nodes, but to the bones and organs like the liver and brain as well. 
  • Anaplastic: Less than 1% of thyroid cancers are of the anaplastic type, but it is the most deadly and appears much like a goiter (a large lump visible under the skin). It too is associated with radiation exposure and spreads near and far very quickly, requiring aggressive treatment.

Treatment of Thyroid Cancer

Treatment is largely dependant on the type, but in most cases the thyroid is completely removed. If the cancer isn’t very large, only a part may be removed. In some situations where the cancer has spread, the lymph nodes may have to come out as well. The normal risks of surgery (bleeding and infection) are always present, but it’s possible for other damage to occur as well, particularly to the vocal cords. If the thyroid is removed completely, your doctor will prescribe a hormone replacement, which you may be on for the rest of your life.

Other options include radiation, chemotherapy, or radioactive iodine therapy. If the cancer is very small, in a difficult to reach location, reoccuring, and doesn’t spread beyond the neck, alcohol ablation may be an alternative. Small amounts of alcohol are injected into the cancerous portions. If the cancer is very advanced, targeted drug therapy, in which medications such as cabozantinib are taken; these drugs target the cancerous cells and interfere with their ability to grow.

Last Updated: June 28, 2016