Q: I am 41 years old. My CA125 blood test shows observed level as 16.6. Does this mean I have cancer?

A:CA 125 (cancer antigen 125) is a protein whose levels are increased in most patients with Stage 3 and 4 ovarian cancers while only about half the patients show raised levels in early stage. It can also be elevated in many non-cancerous diseases of the reproductive tract like endometriosis, pelvic Inflammatory disease, uterine fibroids and adenomyosis, ectopic pregnancy and benign ovarian tumours. As the test gives too many false positives, it cannot be used as a tool for screening. Moreover, it cannot be used to screen for ovarian cancer, as it is not raised in the early stages of the disease. The rate at which CA-125 levels increase is a more accurate method of detecting the presence of ovarian cancer, than a single CA-125 test. A level of greater than 35 U/ml is generally accepted as being high.