Measurement of the serum concentration of the CA 125 glycoprotein antigen is the most widely studied biochemical method of screening for ovarian cancer. Serum CA 125 values are elevated in approximately 50 percent of women with early-stage disease and in over 80 percent of women with advanced ovarian cancer. However, the specificity of CA 125 is limited.
CA 125 levels are elevated in approximately 1 percent of healthy women and fluctuate during the menstrual cycle. CA 125 is also increased in a variety of benign and malignant conditions, including: Endometriosis Uterine leiomyoma Cirrhosis with or without ascites Pelvic inflammatory disease Cancers of the endometrium, breast, lung, and pancreas Pleural or peritoneal fluid due to any cause Mean CA 125 levels further vary with ethnicity and smoking status (lower in non-white women and current smokers) and increase with age. Nonetheless, a…
