CA 125 belongs to the family of hybridoma‑defined tumour markers.
Elevated values are sometimes found in various nonovarian malignancies including cervical, liver, pancreatic, lung, colon, stomach, biliary tract, uterine, fallopian tube, breast, and endometrial carcinomas.
Elevated serum CA 125 levels have been reported in individuals with a variety of nonmalignant conditions including: cirrhosis, hepatitis, endometriosis, first trimester pregnancy, ovarian cysts, and pelvic inflammatory disease. Elevated levels during the menstrual cycle also have been reported.
Although CA 125 is a relatively unspecific marker it is today the most important tumour marker for monitoring the therapy and progress of patients with serous ovarian carcinoma and predicting recurrent ovarian cancer or intraperitoneal tumour.