Tumor Markers for Breast Cancer

What are tumor markers?

Tumor markers are made by cancer cells or other cells when your body responds to cancer. For breast cancer, they are measured with a blood test. A high level of a tumor marker can mean there is cancer in the body, but this test is not enough on its own to diagnose cancer. Other things can raise tumor marker levels.

Tumor markers may be used with other tests to help diagnose cancer. Some markers can help your provider learn more about your prognosis and choose the best treatment. In breast cancer, tumor markers are most often used to test your response to cancer treatment or to watch for recurrence (the cancer coming back). A decrease in the level of a tumor marker may mean that the cancer is responding to treatment. If there is no change or the tumor marker increases, this may mean that the treatment is not working or that the cancer has returned. These results are reviewed along with radiology tests, your physical exam, and any changes in your symptoms. The tumor marker alone doesn't give your provider a full picture.

What are the limits to using tumor markers?

There are some limits to the use of tumor markers. Some non-cancer problems can raise your tumor marker levels. Not everyone with breast cancer will have high tumor markers. Your provider will tell you if they recommend tumor marker testing for you.

Tumor Marker Blood Tests for Breast Cancer

• CA 15-3.
• CA 27.29.
• CA 125.
• Carcinoembryonic antigen (CEA).

Further Reading

OncoLink Patient Guide to Tumor Markers

Read more about breast cancer at OncoLink.org