Hi, Thanks for posting in HCM. I understand your concern. CA 125 (cancer Antigen 125) is a protein substance, which is a tumor marker or cancer biomarker. This substance is found in greater concentration in tumor cells than in other cells of the body. In particular, CA 125 is present in greater concentration in ovarian cancer cells than in other cells. The normal values for CA 125 is 0 to 35 units/ml. A number of benign conditions can cause elevations of the CA 125 level, including pregnancy, endometriosis, uterine fibroids (benign tumors), pancreatitis, normal menstruation, pelvic inflammatory disease, and cirrhosis of the liver. Increase can also be seen in cancers other than ovarian cancer, including malignancies of the uterine tubes, endometrium, lung, breast, pancreas, and gastrointestinal tract as well as lymphoma. It is not possible to interpret the meaning of abnormally high CA 125 results without additional information about the particular patient being evaluated. Generally, decreasing level indicates that therapy, including chemotherapy, has been effective, while an increasing level indicates tumor recurrence. Because of normal test variation, small changes are usually not considered significant. A doubling or halving of the previous value would be important. Hence, you may require clinical examination and additional investigations like ultrasound and CT scan to know the exact reason behind its increase. Hope the information provided would be helpful. All the best. Regards, Dr.Ashakiran.S., MBBS., MD.