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CA 125 test: A screening test for ovarian cancer?

Medically reviewed by Last updated on Aug 25, 2022.

The cancer antigen 125 (CA 125) blood test generally isn't recommended if you have an average risk of ovarian cancer.

Sometimes ovarian cancer causes a higher level of CA 125 in the blood. But that doesn't happen in everyone with ovarian cancer. Having a high level of CA 125 doesn't mean that you have ovarian cancer.

Many other conditions can raise your CA 125 level, including:

  • Endometriosis
  • Liver cirrhosis
  • Menstruation
  • Pelvic inflammatory disease
  • Uterine fibroids

For these reasons, health care providers don't recommend CA 125 testing in those with an average risk of ovarian cancer.

Providers sometimes recommend CA 125 testing if you have a high risk of ovarian cancer. But not all providers agree on this advice. Your risk might be high if the genes that increase the risk of breast and ovarian cancers run in your family. These genes include BRCA1 and BRCA2.

If you're concerned about your risk of ovarian cancer, ask your provider about screening options and ways to lower your risk.

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