Treatment for Thyroid Cancer

The choice of treatment depends on the type of thyroid cancer, the size of the nodule, the patient’s age, and whether the cancer has spread. Thyroid cancer may be treated with surgery, thyroid hormone treatment, radioactive iodine therapy, external radiation therapy, or chemotherapy. Most patients receive a combination of treatments.

For all four types of thyroid cancer, treatment usually starts with a thyroidectomy—the surgical removal of all or part of the thyroid. Nearby lymph nodes and tissue may also be removed if cancer has invaded neck tissue. Some papillary and follicular cancers that are well contained may require only a lobectomy (partial removal of the thyroid), which usually involves removing one of the lobes and the isthmus.

The two most common thyroid cancers also involve follow-up with radioactive iodine, known as I-131 treatment. Thyroid cancer is the only cancer that is remedied in this way because thyroid cells are the only cells in the body that make thyroid hormone by absorbing iodine. Patients are treated with radioactive iodine to kill any remaining thyroid cells after surgery. Even people who are allergic to iodine can take I-131 therapy safely. The therapy is given as a liquid or capsule that zaps thyroid cancer cells throughout the body as it is carried through the bloodstream.[1]

Medullary and anaplastic cancer cells, however, do not respond to I-131 therapy. External radiation therapy or chemotherapy, or a combination of the two, is the standard treatment for these cancers following surgery. Both of these rare thyroid cancers are unique in their own way.

Medullary tumors, which originate from the parafollicular cells (C cells) that make calcitonin, have a lower cure rate than the two more common thyroid cancers. The 10-year survival rate for medullary thyroid cancer is 90 percent when confined to the thyroid gland, 70 percent with spread to cervical lymph nodes, and 20 percent if spread to distant sites.[2] In addition to the usual thyroid cancer follow-ups, patients diagnosed with medullary tumors generally undergo chest X-rays and have the serum calcitonin levels in their blood checked.

Anaplastic thyroid cancer also originates from C cells, and these tumors are generally the most difficult of all thyroid cancers to treat. Typically occurring in older adults (65 and older), anaplastic thyroid cancer is often characterized by a neck mass that is diffused, very hard, and fast growing. This type of cancer requires a tracheostomy (surgically created opening in the neck leading directly to the trachea, or breathing tube) at least 25 percent of the time and has often spread to the lung at the time of diagnosis.[3] Battling this cancer requires a very aggressive treatment plan that generally includes external beam radiation, chemotherapy, and more-invasive surgeries.

References:

[1] Treatment of Thyroid Cancer by Stage. American Cancer Society Web site. Available at: http://www.cancer.org/docroot/CRI/content/CRI_2_4_4X_Treatment_of_Thyroid_Cancer_by_Stage_43.asp?sitearea=. Accessed September 30, 2008.

[2] Genetics of Medullary Thyroid Cancer (PDQ). National Cancer Institute Web site. Available at: http://www.cancer.gov/cancertopics/pdq/genetics/medullarythyroid/healthprofessional. Accessed September 30, 2008.

[3] What You Need to Know About Thyroid Cancer. National Cancer Institute Web site. Available at: http://www.cancer.gov/cancertopics/wyntk/thyroid. Accessed September 30, 2008.