This blood test checks for raised levels of a protein called CA125.

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 level may be higher in women with ovarian, fallopian tube, or primary peritoneal cancer. The level of CA125 can also be raised by non-cancerous conditions and by other types of cancer.

In early ovarian cancer, CA125 levels may be normal.