CA 125 falls short of being an ideal tumor marker in that it lacks the specificity required to be used as an effective screening tool.
- CA 125 is a mucin tumor marker that is produced primarily by ovarian and endothelial cells.
- Because CA 125 is sometimes produced by non-cancerous endothelial cells of the uterine endothelium, it is not recommended as a screening test for ovarian cancer in non-symptomatic women.
- CA 125 is also produced by some non-ovarian carcinomas of the pancreas, lung, breast, and colon.
- CA 125 is produced with an incidence of over 90% in cases of advanced ovarian cancer, and thus has been used to assist in the diagnosis of ovarian cancer in symptomatic women.6
- Persistently elevated levels of CA 125 after chemotherapy are indicative of a poor prognosis.
- CA 125 is also used to monitor the effectiveness of ovarian cancer treatments, to assess the prognosis of a patient, and to determine recurrence or relapse from a state of remission.7
