The CA 19-9 test measures the level of cancer antigen 19-9 in your blood. CA 19-9 is a protein that can be elevated in certain types of cancer, particularly cancers of the pancreas, liver, gallbladder and digestive tract.
Why it’s important:
- Cancer monitoring: CA 19-9 is most commonly used to monitor patients with pancreatic cancer, as levels can rise in response to the presence of the cancer or its progression.
- Evaluate treatment effectiveness: The test helps assess how well cancer treatments, like chemotherapy or surgery, are working by tracking changes in CA 19-9 levels.
- Detect recurrence: For individuals previously diagnosed with pancreatic or other gastrointestinal cancers, CA 19-9 can be used to detect potential recurrence of the disease.
Limitations of CA 19-9 Testing:
- Not specific to cancer: High CA 19-9 levels can be seen in conditions unrelated to cancer, so it is not used for screening or diagnosing cancer alone.
- False negative in some patients: Not all cancers, especially early-stage cancers, cause an increase in CA 19-9. Additionally, some people may not produce high levels of CA 19-9 even if they have cancer
