by Carson-DeWitt R

Thyroid cancer may not have symptoms. The doctor may notice changes to the thyroid during a normal physical exam. Something may also be found during a scan for another health issue. The doctor will ask about symptoms, past health, and family health history.

Suspicion of Thyroid Cancer

Other conditions can cause a change in the thyroid. They are more common and often easier to treat. Tests will be done to see if the changes may be due to cancer. Tests may include:

  • Blood tests—To look for signs of a tumor growth. Thyroid hormones, calcitonin, and calcium levels can also be measured with blood tests. They can show a change in thyroid function.
  • Imaging tests—To locate tumor and see its size. Imaging tests may include:

Diagnosis of Thyroid Cancer

A biopsy is needed to confirm cancer. A sample of tissue from the growth will be taken. It will be checked in the lab for cancer cells.

The procedure will depend on the type, size, and location of the growth. Options include:

  • Fine needle aspiration (FNA)—A thin needle is used to remove cells and fluid from the area.
  • Core needle—A larger, hollow needle is used to remove a wider area of tissue.
  • Surgical—The entire growth is removed.
  • Lobectomy—The lobe with the growth is removed.

Staging of Thyroid Cancer

Test results will help to know the stage of cancer. The stage is used to help make a treatment plan. Staging is based on how far the tumor has spread. It considers what lymph nodes are involved, and if the cancer has spread to other tissue. Information about the cancer cells will also be needed.

Staging Tests

Tests that may help determine thyroid cancer stage include:

  • Blood tests—To look for changes in blood cells, proteins, or signs of cancer.
  • Imaging tests—To show how much of the thyroid is affected. It can also show if lymph nodes or nearby tissue is involved. It can also show if cancer has spread to other areas of the body. Imaging tests may include:
  • Laryngoscopy—A tube is passed into the throat. It will help the doctor see any changes to throat. It can show if cancer has spread to throat.
  • Sentinel lymph node biopsy—Sentinel lymph nodes are the first nodes that a tumor will drain into. If these nodes are free of cancer cells, it is unlikely that the cancer has spread. If cancer cells are present, then more lymph nodes may need to be removed—to see how far the cancer has spread.
  • Tissue evaluation—Cancer tissue from the biopsy will be more closely examined. There are differences in types of cancer cells. These differences help the doctor know what treatments to use.
Stages of Thyroid Cancer

There are different types of thyroid cancer. The type and details of cells are used for cancer staging and the treatment.

Papillary and Follicular Thyroid Cancer

In people under 45 years old, papillary and follicular thyroid cancers are staged from I to II:

  • Stage I—Any size tumor that MAY be found in nearby structures and lymph nodes. It HAS NOT spread to other parts of the body.
  • Stage II—Any size tumor that HAS spread beyond the thyroid gland to other parts of the body. There are areas where thyroid cancer tends to spread more often. They include the lymph nodes in other parts of the body, the bones, and the lungs.

In people aged 45 years and older, papillary and follicular thyroid cancers are staged from I-IV:

  • Stage I—The tumor is no larger than 2 centimeters (cm) in size and HAS NOT spread beyond the thyroid gland.
  • Stage II—The tumor is 2 to 4 cm in size and HAS NOT spread beyond the thyroid gland.
  • Stage III—Any of the following:
    • The tumor is larger than 4 cm in and HAS NOT spread beyond the thyroid, OR
    • The tumor is any size and HAS spread just beyond the thyroid BUT IS NOT in nearby lymph nodes
    • The tumor is any size AND MAY be found beyond the thyroid in nearby lymph nodes
  • Stage IVA—Any of the following:
    • The tumor is any size AND IS found beyond the thyroid gland. It is in either the esophagus, under the skin, the larynx (or its nerve), or trachea. AND it may be in nearby lymph nodes next to the trachea or larynx.
    • The tumor is any size AND MAY be found beyond the thyroid. AND it is found in nearby lymph nodes around the neck (either or both sides) or between the lungs.
  • Stage IVB—The tumor is found beyond the thyroid gland:
  • Near the spinal column or around the carotid artery (in the neck), OR
  • The blood vessels between the lungs, AND
  • MAY be in the lymph nodes
  • Stage IVC—The tumor is found beyond the thyroid . Common sites for thyroid cancer to spread are the lymph nodes in other parts of the body, the bones, and the lungs.
Medullary Thyroid Cancer

Medullary thyroid cancer is staged from 0 to IV:

  • Stage 0—There is no tumor present, but cancer is found by specific screening tests.
  • Stage I—The tumor is no larger than 2 centimeters (cm) and HAS NOT spread beyond the thyroid.
  • Stage II—Any of the following:
    • The tumor is larger than 2 cm in size and HAS NOT spread beyond the thyroid gland.
    • The tumor is any size and HAS spread just beyond the thyroid gland BUT NOT to nearby lymph nodes.
  • Stage III—The tumor is any size AND MAY be found beyond the thyroid. AND it may be found in lymph nodes near the trachea and larynx.
  • Stage IVA—Any of the following:
    • The tumor is any size AND IS found beyond the thyroid. It may be in either the esophagus, under the skin, the larynx (or its nerve), or trachea. AND it may also be in nearby lymph nodes near the trachea or larynx.
    • The tumor is any size AND MAY be found beyond the thyroid. AND it is found in nearby lymph nodes around the neck (either or both sides) or between the lungs.
  • Stage IVB—The tumor is found beyond the thyroid near the spine. OR the tumor is:
  • Around the carotid artery (in the neck), OR
  • The blood vessels between the lungs, AND
  • It MAY be in the lymph nodes
  • Stage IVC—The tumor is found beyond the thyroid gland. Common sites for thyroid cancer to spread are lymph nodes in other parts of the body, the bones, and the lungs.
Anaplastic Thyroid Cancer

Anaplastic thyroid cancer is always stage IV:

  • Stage IVA—The tumor is found in the thyroid gland—and MAY be in the lymph nodes.
  • Stage IVB—The tumor is found beyond the thyroid gland—and MAY be in the lymph nodes.
  • Stage IVC—The tumor is found beyond the thyroid. Common sites for thyroid cancer to spread are lymph nodes in other parts of the body, the bones, and the lungs.

Prognosis (Outlook)

Papillary and follicular thyroid cancers are among the least harmful cancers when treated. If detected early, nearly all people survive 5 years or more. If the cancer has spread, a little more than half of people survive.

Medullary thyroid cancers have similar survival rates—unless the cancer spreads to other areas of the body. In this case, about 1/4th of all people survive 5 years or more.

Anaplastic thyroid cancer is the most fatal type. It spreads fast and is hard to treat. About 10 out of 100 people survive 5 years with it. Almost all deaths occur within the first year of diagnosis.

References

Anaplastic thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/anaplastic-thyroid-cancer. Accessed April 20, 2022.

Filetti S, Durante C, et al. Thyroid cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2019;30(12):1856-1883.

Follicular thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/follicular-thyroid-cancer-21. Accessed April 20, 2022.

Medullary thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/medullary-thyroid-cancer. Accessed April 20, 2022.

Papillary thyroid cancer. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/papillary-thyroid-cancer. Accessed April 20, 2022.

Stages of thyroid cancer. National Cancer Institute website. Available at: https://www.cancer.gov/types/thyroid/patient/thyroid-treatment-pdq#section/%5F27. Accessed April 20, 2022.

Tests for thyroid cancer. American Cancer Society website. Available at: https://www.cancer.org/cancer/thyroid-cancer/detection-diagnosis-staging/how-diagnosed.html. Updated Accessed April 20, 2022.

Thyroid cancers. Merck Professional Version website. Available at: http://www.merckmanuals.com/professional/endocrine-and-metabolic-disorders/thyroid-disorders/thyroid-cancers. Accessed April 20, 2022.

Treatment option overview. National Cancer Institute website. Available at: https://www.cancer.gov/types/thyroid/patient/thyroid-treatment-pdq#section/%5F67. Accessed April 20, 2022.

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