A tumor marker associated with ovarian cancer.
Cancer antigen 125, or CA-125, is a protein found on the surface of many cells, including those of the ovary. A small amount circulates in the blood of healthy people.
It is measured as a tumor marker, most often in the context of ovarian conditions, but it is not specific to cancer.
CA-125 is used mainly to monitor people already diagnosed with ovarian cancer and to help assess certain pelvic masses, alongside imaging and exam. It is not a screening test for healthy women, because many benign conditions raise it.
Levels can go up with menstruation, endometriosis, fibroids, pelvic inflammation, pregnancy, and liver disease. A raised result is common and usually benign, so it always 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-125 is an upper-cutoff marker.
| Group | Common upper guide (SI) |
|---|---|
| Adults | up to about 35 kU/L (U/mL) |
Benign causes often raise it modestly. Aligned to German laboratory practice (DGKL).
Menstruation, endometriosis, fibroids, pelvic inflammatory disease, pregnancy, and liver disease can all raise CA-125. Results from different assays are not interchangeable, so trends should be followed on the same method.
Read alongside pelvic imaging and clinical exam, and sometimes other markers such as HE4 when assessing a pelvic mass.
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