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What Is Thyroid Cancer?

Front view of head and neck showing trachea and thyroid gland.

Cancer happens when cells in the body change and grow out of control. These cells can form lumps of tissue called tumors. Cancer that starts in cells of the thyroid is called thyroid cancer.

Understanding the thyroid

The thyroid is a small, butterfly-shaped gland in front of the neck, just below the Adam's apple. The thyroid controls the rate at which every part of the body works. This is called metabolism. The thyroid gland regulates the metabolism by making thyroid hormone, a chemical that carries messages from the thyroid to the rest of the body through the bloodstream. The thyroid also makes the hormone called calcitonin. This regulates how calcium is used in the body. 

When thyroid cancer forms

Cells in the thyroid may grow out of control, forming small lumps called nodules. But most thyroid nodules are not cancer. The thyroid may also enlarge (swell). Thyroid cancer can spread from the thyroid to other parts of the body. This spread is called metastasis. In general, the more cancer spreads, the harder it is to treat.

There are four main types of thyroid cancer (also called thyroid carcinoma):

  • Papillary carcinoma, which is the most common type

  • Follicular carcinoma

  • Medullary thyroid carcinoma

  • Anaplastic carcinoma 

Treatment choices for thyroid cancer

There are different types of thyroid cancer. You and your healthcare provider will discuss a treatment plan that is based on your type of cancer and your personal  needs. Treatment choices may include:

  • Surgery to remove part or all of the thyroid gland

  • Radioiodine therapy, which uses radioactive iodine to destroy thyroid cancer cells in the body

  • External radiation therapy, which uses rays of energy directed right at the tumor to kill cancer cells

  • Hormone therapy, which blocks or removes the hormones that help the cancer grow

  • Chemotherapy, which uses strong medicines to kill cancer cells throughout the body

  • Targeted therapy, which targets the cancer cells' genes or proteins that allow cancer growth and survival

  • Watchful waiting, with frequent healthcare check-ups to look for any problems or symptoms that have developed since your last appointment

If you have questions about thyroid cancer, talk with your healthcare provider. He or she can help you understand more about this cancer.

Online Medical Reviewer: Hurd, Robert, MD
Online Medical Reviewer: Stump-Sutliff, Kim, RN, MSN, AOCNS
Date Last Reviewed: 6/1/2018
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