The Autobio cancer antigen 125 (CA125) chemiluminescence immunoassay (CLIA) kit is intended for the quantitative determination of CA125 concentration in human serum.
Cancer Antigen 125 (CA125) is a surface antigen associated with epithelial ovarian cancer. In serum, CA125 is associated with a high molecular weight glycoprotein. Published studies have indicated that elevated serum CA125 levels can be found in individuals with serious endometroid, clear-cell and undifferentiated ovarian carcinoma. Serum CA125 levels higher than normal can also be found in individuals with adenocarcinoma of the fallopian tube endometrium, certain non-gynecologic malignancies and some non-malignant conditions.
Serum CA 125 assay values are useful for monitoring the course of disease in patients with invasive epithelial ovarian cancer. In a review of nine published studies, the overall correlation reported between CA 125 serum levels and the course of the disease was 87%. Serum levels of CA125 greater than 35 units per ml, combined with pelvic examination increases the test specificity. Serial determinations of serum CA125 further enhances the positive predictive value of the test for ovarian cancer. Serum CA125 concentration may be useful in monitoring patients with diagnosed ovarian cancer. Persistently rising CA 125 assay values may be associated with malignant disease and poor response to therapy, whereas decreasing CA 125 assay values may indicate a favorable response to therapy.
In women with primary epithelial ovarian carcinoma who had undergone first-line therapy and were candidates for diagnostic second-look procedures, a CA 125 assay value greater than or equal to 35 U/ml was found to be indicative of the presence of residual tumor. However, a CA125 assay value below 35 U/ml does not indicate the absence of residual ovarian cancer because patients with histopathologic evidence of ovarian carcinoma may have CA125 assay values within the range of normal individuals.
Elevations of CA125 assay values have been reported in approximately 1-2% of healthy individuals, and in individuals with nonmalignant conditions such as cirrhosis, hepatitis, endometriosis, first trimester pregnancy, ovarian cysts, and pelvic inflammatory disease. Elevations of CA125 assay values during the menstrual cycle have also been reported. Non-ovarian malignancies in which elevated CA125 assay values have been reported include cervical, liver, pancreatic, lung, colon, stomach, biliary tract, uterine, fallopian tube, breast, and endometrial carcinomas.
To date, CA125 is the most sensitive marker for residual epithelial ovarian cancer.
