Thyroid cancer is one of the fastest growing cancers diagnosed in the U.S., as the incidence over the last 30 years has doubled. Much of this increase can be attributed to the increase in detection, as the disease if often picked up during imaging for another medical issue. For example, thyroid nodules are often seen on cervical spine MRI/CT scans, or on carotid artery ultrasounds.

The American Cancer Society estimates that approximately 62,450 new cases of thyroid cancer are diagnosed each year, with nearly 3 out of 4 cases found in women. The good news is that the death rate remains very low at about 1,980 each year. The following are some of Mount Sinai’s patients’ most frequently asked questions about thyroid cancer.

Q: What is the thyroid gland?
The thyroid is the butterfly-shaped gland located in the front, lower portion of the neck. It secretes thyroid hormones, which regulate the heart rate, body temperature, blood pressure and metabolism. Thyroid hormones help the body to use energy and function normally.

Q: What are the symptoms of thyroid cancer?
Most patients do not experience symptoms, but among those who do, the most common is a lump or swelling in the neck, which is usually painless. Other less common symptoms include difficulty swallowing and breathing, swelling of the sides of the neck, persistent cough unrelated to a cold or other illness, or throat discomfort or tightness.

Q: What causes thyroid cancer and what are the risk factors of it?
There is no known cause of thyroid cancer; however, there are several risk factors that increase your chance of developing the disease. These include:

• A diet low in iodine
• A family history of thyroid cancer
• History of goiter (enlarged thyroid)
• Exposure to radiation in the head, neck, and chest areas
• Females over the age of thirty (more likely to develop the disease than men)
• Genetic conditions such as familial medullary thyroid cancer (FMTC), multiple endocrine neoplasia (MEN) type 2A syndrome, and multiple endocrine neoplasia (MEN) type 2B syndrome

Q: How is thyroid cancer diagnosed?
Thyroid nodules are usually discovered by a doctor during a physical exam, or incidentally on imaging as mentioned previously. A cancerous nodule can be confirmed by an office biopsy (fine-needle aspiration biopsy of the thyroid) of the nodule or microscopically examining a surgically removed nodule. Thyroid nodules are very common, and fewer than 1 in 10 are cancerous.

Q: What are the types of thyroid cancer?
There are several types of thyroid cancer. Papillary thyroid cancer is the most common type, accounting for about 80 percent of all thyroid cancers. It can occur at any age and often spreads to the lymph nodes in the neck, but has a very high cure rate if caught early. Follicular carcinoma is the second most common type of thyroid cancer and also has a good prognosis if caught early. Medullary thyroid cancer is more likely to run in families and may be diagnosed by genetic testing. The rarest form, known as anaplastic thyroid cancer, quickly invades other parts of the body, is least likely to respond to treatment, and is often fatal.

Q: What treatments are available?
Thyroid cancer is primarily treated by a thyroidectomy, or the surgical removal of the thyroid. Small cancers may even be treated by partial thyroidectomy. Radioactive Iodine (RAI) therapy may also be used following surgery to destroy any remaining thyroid cells, cancerous and noncancerous, without affecting the rest of the body. Thyroid cancer patients very rarely need chemotherapy or radiation and if caught early, the prognosis for thyroid cancer is very good. Follow-up tests (CT, MRI, ultrasounds, PET) may also be performed to monitor patients.

Q: If my thyroid is removed, will I need to take medication for the rest of my life?
Yes, all patients who undergo a total thyroidectomy will need to take thyroid hormone replacement medication for life. The medications replace the thyroid hormones, which regulate your metabolism and bodily functions. Your endocrinologist will work closely with you to determine the optimal level of medication for your body.

Last updated: September 5, 2016