CA125 measurement by chemiluminescent immunoassay on the ADVIA Centaur
CA125 is a high molecular mass glycoprotein recognised by the monoclonal antibody OC 125. It is expressed by epithelial ovarian tumours as well as both pathological and non-pathological tissues of Müllerian duct origin. CA125 is also elevated in non-ovarian carcinoma such as endometrial, lung, pancreatic and breast, colorectal, and other gastrointestinal tumours. Measurement is useful in determining the prognosis of endometrial carcinoma. CA 125 may be useful in detecting residual disease in cancer patients following initial therapy as well as monitoring response to therapy. Elevated CA125 may also be found during the follicular phase of the menstrual cycle in women as well as benign conditions such as ascites, cirrhosis, hepatitis, endometriosis, and early pregnancy. Measurement cannot be used to differentiate between ovarian cancer and other malignancies nor should it be used to screen for ovarian cancer in asymptomatic populations.