Thyroid Cancer

Thyroid cancer begins in the thyroid glands, which are located inside the front of the lower neck. The thyroid has two types of cells: follicular cells, which use iodine from the blood to create hormones that regulate the metabolism, and C cells, which make calcitonin, a hormone that regulates the body’s use of calcium. Distinct cancers develop from each type of thyroid cell. These differences are important because they determine the seriousness of the cancer and the needed treatment. Almost 66 percent of cases of this cancer are found in patients under 551.

Credit: American Cancer Society

What are the different types of thyroid cancer?

There are several types of thyroid cancer that affect the different cells of this gland. Read more about the types of thyroid cancer.

What are the symptoms of thyroid cancer?

Thyroid cancer does not typically have signs or symptoms in its early stages. Some symptoms are:

  • A lump that can be felt through the skin on the neck
  • Changes in the voice, including increasing hoarseness
  • Difficulty swallowing
  • Pain in your neck and throat
  • Swollen lymph nodes in your neck
  • Trouble breathing
  • Constant cough that is not due to a cold
  • Swelling in the neck

How is thyroid cancer diagnosed?

Physical exams consist of feeling the neck and checking for the thyroid lumps and lymph node swelling.

Blood tests determine if the thyroid is functioning normally and help determine what other tests may be needed. Blood tests for thyroid cancer include thyroid-stimulating hormone (TSH) tests, T3 and T4 hormone measurements, Thyroglobulin measurements, Calcitonin measurements, Carcinoembryonic antigen (CEA) measurements.

Imaging tests use x-rays, magnetic fields, or sound waves to create pictures of the inside of the body. For thyroid cancer, these tests include ultrasounds, radioiodine scans, chest x-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI) scans, and positron emission tomography (PET) scans.

Biopsy is the removal of tissue from the thyroid for examination under the microscope. Biopsy is the only way to make a thyroid cancer diagnosis and determine its type.

What are the different stages of thyroid cancer?

The most common system used to stage thyroid cancer is the TNM Staging Classification for Thyroid Cancer.

The TNM system describes 3 key pieces of information:

  • T indicates the size of the main (primary) tumor and whether it has grown into nearby areas.
  • N describes the extent of spread to nearby (regional) lymph nodes. Lymph nodes are bean-shaped collections of immune system cells to which cancers often spread first. Cells from thyroid cancers can travel to lymph nodes in the neck and chest areas.
  • M indicates whether the cancer has spread (metastasized) to other organs of the body. (The most common sites of spread of thyroid cancer are the lungs, the liver, and bones.)

What are the treatments for thyroid cancer?

This thyroid cancer treatment information does not outline the particular treatment(s) a patient will receive. Rather, it provides general information about the typical treatments for this type of cancer.

Surgery consists of removing all or most of the cancerous tumor in the thyroid. For thyroid cancers, these procedures include lobectomy, thyroidectomy and lymph node removal.

Thyroid hormone therapy is the delivery of medication (levothyroxine, levothroid, Snythroid and others) to replace the loss of natural thyroid hormones after removal of part or the entire thyroid. Medical professionals have discovered giving patients higher than normal doses of synthetic thyroid hormone slows the growth of any remaining cancer cells.

Radioactive iodine therapy is often used after a thyroidectomy to destroy any thyroid tissue remaining after surgery. Since the thyroid gland absorbs nearly all iodine taken into the body, the radioactive component of a radioactive iodine dosage is able to destroy remaining thyroid tissue.

Radiation therapy uses high-energy rays or particles to kill cancer cells. This type of treatment is generally used if cancerous cells do not respond to radioiodine therapy. This therapy can be used to treat thyroid cancer recurrence or distant metastases (spreading of the cancer).

What are the risk factors of thyroid cancer?

  • Exposure to high levels of radiation: Radiation to the head and neck as a result of proximity to nuclear power plants or weapon testing increases the chances of developing thyroid cancer.
  • Genetic syndromes: Certain inherited syndromes, like familial medullary thyroid cancer, multiple endocrine neoplasia and familial adenomatous polyposis, are correlated to higher rates of thyroid cancer.
  • Gender: Thyroid cancer is 3 times more prevalent in women than it is in men.
  • Age: Women between the age of 40-50 and men between the ages of 60-70 are at the highest risk of developing thyroid cancer.

How is thyroid cancer prevented?

  • Avoiding of high-levels of radiation, especially for children.
  • Identifying the presence of familial medullary thyroid cancer (MTC); if identified early, MTC may be prevented by removing the thyroid glands
Mikayla D. Williams , BS student, Nursing , The University of Arizona
Michael Principe, MA, Information Resources and Library Science , The University of Arizona
Works Cited: 
American Cancer Society (2014). Thyroid cancer.
Works Consulted: