CA 125

This blood test seeks raised levels of CA 125, a protein that is present on the surface of most, but not all, ovarian cancer cells. This makes the test useful as a 'tumour marker' in specific circumstances. Significantly elevated concentrations of CA 125 may be present in the blood of a woman who has ovarian cancer. Small quantities of CA 125 are produced by normal tissues throughout the body and by some other cancers (including bowel) - but it is important to emphasize a higher level does not mean cancer is always present. Levels in the blood may be moderately elevated with a variety of non-cancerous conditions, including menstruation, pregnancy, and pelvic inflammatory disease.