Useful For

The VITROS CA 125 II (C125a) test is a second generation test for the detection of OC 125 defined antigen on a high molecular weight glycoprotein in serum.

CA 125 test concentrations are elevated in most patients with active epithelial ovarian cancer (OC), including those with stage I disease. CA 125 test concentrations are elevated in 1-2% of healthy individuals and may be elevated in diseases other than ovarian carcinoma, including both benign and malignant disorders.

In women with primary epithelial ovarian carcinoma who have undergone first-line therapy and are candidates for diagnostic second-look procedures, a CA 125 test concentration greater than or equal to 35 U/mL has been found to be indicative of the presence of residual tumor. Assuming the physician cannot identify alternative causes for an elevated CA 125 test concentration, a CA 125 test concentration greater than or equal to 35 U/mL provides substantial evidence that residual tumor is present. A CA 125 test concentration below 35 U/mL does not indicate the absence of residual ovarian cancer because patients with histopathologic evidence of ovarian carcinoma may have CA 125 test concentrations within the range of healthy individuals. Clinical decisions should not be based on Vitros CA 125 test concentrations below 35 U/mL.