The thyroid gland is a small, butterfly-shaped organ located in the front of the neck. It is a part of the endocrine system and regulates the levels of thyroid hormone in the body.
Thyroid cancer occurs when cells in the thyroid gland become neoplastic (uncontrolled growth). Almost 37,000 new cases of thyroid cancer are diagnosed each year in the United States, with most patients between the age of 20 and 55. Women are three times more likely to develop thyroid cancer than men. This cancer is generally associated with an excellent prognosis, with most patients cured with relatively simple treatment.
Types of thyroid cancer include:
· Papillary thyroid cancer
· Follicular thyroid cancer
· Medullary thyroid cancer
· Anaplastic thyroid cancer
Symptoms of Thyroid Cancer
Most thyroid cancer is identified after finding a mass in your neck - either as a mass felt by you or your physician, or as an incidental finding on routine imaging (ultrasound, CT scan, MRI) done for other reasons.
In the early stages of thyroid cancer, most people have no symptoms. As the cancer progresses, however, some people will experience difficulty swallowing, discomfort in the throat or neck, voice changes or hoarseness, or swollen lymph nodes in the neck. Importantly, these symptoms are usually due to non-cancerous conditions such as a goiter or a benign thyroid nodule.
The following factors may increase a person’s risk of developing thyroid cancer: low-dose radiation exposure (especially as a child) and a family history of thyroid cancer (especially in cases of medullary thyroid cancer).
How Thyroid Cancer is Diagnosed
The diagnosis of thyroid cancer often involves a combination of physical exam, blood tests, ultrasound, and needle biopsy.
Ultrasound is commonly used to evaluate thyroid nodules and can often identify a nodule that is suspicious for cancer. A sample of tissue (needle biopsy) is then obtained and examined under the microscope. The biopsy is usually performed in the outpatient clinic as a thin needle is inserted into the thyroid nodule (fine needle aspiration biopsy). Depending on the results of the biopsy, surgery may be needed to remove part or all of the thyroid gland.
For patients with cancer, a radioactive iodine scan (RAI) is often done following surgery to determine whether thyroid cancer has spread to other parts of the body (diagnostic scan). During this test, a patient swallows a capsule that contains radioactive iodine. The iodine is absorbed by any remaining thyroid tissue and thyroid cancer cells. If there is persistent uptake of iodine following the surgery, this suggests that there is still some active thyroid tissue or thyroid cancer remaining. Those patients will then be treated with a stronger dose of radioactive iodine (single treatment/therapeutic dose). These decisions will be explained to you by your endocrinologist.
Staging of thyroid cancer is determined by the age of the patient, the size of the nodule or cancer, and whether the cancer has spread to sites outside the thyroid gland. Thyroid cancer spreads most often to the lymph nodes (common), lungs (uncommon), and bones (uncommon). If spread (metastases) has occurred, some patients may need more extensive surgery, while some patients can be managed with radioactive iodine.
Treatment Options for Thyroid Cancer
Most people with thyroid cancer will be treated with surgery, although the specifics of the surgery depend on the type of thyroid cancer (papillary, follicular, medullary, or anaplastic), the size of the cancer, the presence or absence of lymph node metastases, and the patient’s age and general health.
Most people with thyroid cancer have surgery. The majority of patients with low risk thyroid cancer can be cured with surgery and require little or no further treatment. The surgeon may remove all or part of the thyroid. The following are possible types of surgeries to treat thyroid cancer:
· Total thyroidectomy. Removal of the entire thyroid.
· Thyroid lobectomy. Removal of one lobe of the thyroid only. This is done in certain cases of low-risk papillary or follicular thyroid cancer. This decision will be discussed with you by your surgeon and/or endocrinologist.
The following are common non-surgical treatments for thyroid cancer:
· Radioactive Iodine Therapy. Many patients with papillary or follicular thyroid cancer will be treated with radioactive iodine following their surgery. Radioactive iodine therapy can destroy thyroid cancer cells that remain after surgery. This therapy is not effective for medullary or anaplastic thyroid carcinoma, since they do not absorb iodine.
· Thyroid Hormone Treatment. The thyroid gland has one primary function – it makes thyroid hormone (essential for normal functioning of many body systems). Patients who have their entire thyroid gland removed must take a daily thyroid hormone pill to replace the missing hormone. Patients treated with a thyroid lobectomy alone will also typically take thyroid hormone, as thyroid hormone is thought to help prevent recurrence of the thyroid cancer.
Clinical Trials Available for Patients
Our patients have access to novel therapies through participation in both Tufts Medical Center clinical trials and national clinical trials.
For more information about Tufts Medical Center’s Head and Neck Cancer Program and our expert medical resources
Thyroid Cancer Links
American Thyroid Association, Thyroid Cancer Brochure:
American Thyroid Association, Thyroid Nodule Brochure: