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. Tumor markers for breast cancer can be found in the blood and are checked using a blood test. A high level of a tumor marker can mean that cancer is in the body, but is not enough to diagnose cancer. There could be other reasons for a high level.

Tumor markers may be used with other tests to help diagnose cancer. Some markers can help figure out 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 must be reviewed along with radiology tests, your physical exam, and the increase or decrease in any symptoms you may be having. The tumor marker level alone is not enough for a clear picture of your cancer.

What are the limits to using tumor markers?

There are some limits to the use of tumor markers. There are non-cancerous problems that can cause tumor markers to be high. Not everyone with breast cancer will have an increase in a tumor marker. Your care team will tell you if they recommend you have testing done for tumor markers.

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