CA125 blood test

This blood test checks for raised levels of a protein called CA125. It helps diagnose or monitor ovarian, fallopian tube or primary peritoneal cancer.

You may have a CA125 blood test during diagnosis or after treatment for ovarian cancer, fallopian tube cancer or primary peritoneal cancer.

This blood test checks for raised levels of a protein called CA125. It is normal to have some CA125 in the blood. But the levels may be higher if you have ovarian cancer.

A CA125 test is not reliable enough to be used on its own in ovarian cancer. The level of CA125 can also be raised due to non-cancerous conditions and other types of cancer. Sometimes in early ovarian cancer, CA125 levels may be normal.

Your GP or hospital doctor will arrange for you to have a CA125 blood test. If your CA125 levels are raised (35 IU/ml or above) you should have an ultrasound scan of your pelvis.

You may also have CA125 blood tests to help monitor how your treatment is working and as part of your follow-up after treatment. 

Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.