Tumor Marker Tests
Reviewed
Tumor marker tests measure substances made by cancer cells or normal cells in response to cancer. They are most often used after a cancer diagnosis to help stage cancer, predict growth, select treatment, monitor therapy, or detect recurrence. Some tests have a limited role in screening people at high risk, but they cannot diagnose cancer—a biopsy is usually needed. Results must be interpreted by your healthcare professional along with other information.
Preparation and collection
For a blood or urine test: no special preparations. For a biopsy: you may need to fast (not eat or drink) for several hours before the procedure. Follow your provider's instructions.
Understanding this test
Use the reference interval and units printed by the laboratory that performed the test. A result outside that interval is not a diagnosis by itself, and a result inside it does not rule out every condition. Your symptoms, history, medicines, timing, and related tests can change what the result means.
- Not all cancers have known tumor markers.
- Some non-cancer conditions can cause high levels of certain tumor markers.
- Some people with cancer do not have elevated levels of the commonly tested markers.
- Tumor marker tests cannot diagnose cancer; a biopsy is usually needed.
What to do next
Your provider will discuss your results and recommend any follow-up tests or procedures, such as imaging or biopsy, based on your specific situation.