CA 15-3 and CA 27-29- Why am I having this test?
CA 15-3 and CA 27-29 are tumor markers that are used primarily for monitoring your response to treatment for breast cancer.
CA 15-3 (cancer antigen 15-3) and CA 27-29 (cancer antigen 27-29) tumor marker tests may be used to help determine the stage of your breast cancer and to monitor your response to treatment. They may be used along with other tests to guide your care. These tests are not used to screen for cancer.
What is being tested?
The tests measure the levels of CA 15-3 and CA 27-29 in your blood. Decreasing levels may suggest a good response to cancer treatment. Rising levels may suggest cancer progression.
What kind of sample is taken?
A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel.
How are the results reported?
Your test results will be reported as values. Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, common reference ranges are:
- CA 15-3: Less than 31 units/mL or less than 31 kunits/L (SI units).
- CA 27-29: Less than 38 units/mL or less than 38 kunits/L (SI units).
What do the results mean?
- Increased levels of CA 15-3 or CA 27-29 may indicate that your breast cancer is spreading (metastatic breast cancer). Increased levels may also be found with liver cancer, pancreatic cancer, ovarian cancer, and colorectal cancer. Elevated levels may also occur with benign breast and liver disease.
- Decreased levels of CA 15-3 or CA 27-29 may suggest a good response to cancer treatment.
Talk with your health care provider about what your results mean.
Questions to ask your health care provider
Ask your health care provider, or the department that is doing the test:
- When will my results be ready?
- How will I get my results?
- What are my treatment options?
- What other tests do I need?
- What are my next steps?
Summary
- The CA 15-3 and CA 27-29 tumor marker tests may be used to help determine the stage of your breast cancer and to monitor your response to treatment.
- Levels of CA 15-3 or CA 27-29 that are above the reference ranges may indicate that your breast cancer is spreading.
- Decreasing levels of CA 15-3 or CA 27-29 may indicate that your breast cancer is responding well to cancer treatment.
- Talk with your health care provider about what your results mean.
