A tumor marker linked to pancreatic and biliary cancers.
Cancer antigen 19-9, or CA 19-9, is a sugar-protein marker found on the surface of some cells, including those of the pancreas and bile ducts. Small amounts circulate in healthy people.
It is measured as a tumor marker. A small share of people genetically cannot produce CA 19-9, so it is undetectable in them even if cancer is present.
CA 19-9 is used mainly to monitor people already diagnosed with pancreatic or bile duct cancer, alongside imaging. It is not a screening test for healthy people, as benign conditions commonly raise it and some cancers do not.
Mild rises are often benign and can come from blocked bile ducts, gallstones, pancreatitis, liver disease, and diabetes. A high or rising level needs a doctor to interpret in context.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
Ranges are guidance only. CA 19-9 is an upper-cutoff marker.
| Group | Common upper guide (SI) |
|---|---|
| Adults | up to about 37 kU/L (U/mL) |
The exact cutoff depends on the assay. Aligned to German laboratory practice (DGKL).
Blocked bile flow, gallstones, pancreatitis, liver disease, and diabetes can raise CA 19-9 without cancer. People who lack the Lewis blood group antigen do not make it, so it can be falsely undetectable. Different assays are not interchangeable.
Sometimes read alongside CEA and liver function tests, and always with imaging and clinical history.
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