- Last Update On : 2013-09-02
CA-125 is a cell surface glycoprotein associated with ovarian carcinoma cells, but not normal adult ovarian cells. It is expressed on the surface of serous, endometrioid, clear cell, mucinous, and undifferentiated tumors of the ovary, but less often by Brenner, sex cord, and germ cell ovarian tumors. It is a normal constituent of fallopian tube, endocervix, and endometrium. CA-125 also occurs in mesothelial cells lining the adult pleura, pericardium, and peritoneum. CA-125 is not specific for ovarian cancer, but can also be elevated in patients with pancreas, breast, colon and lung cancer.
Elevated CA-125 levels have been observed in many different conditions. CA-125 levels are higher in healthy women less than 49 years old than in healthy women over 49 years and in healthy men, presumably due to the effect of menstruation. The expression of CA-125 in normal endometrium and decidual endometrium accounts for the elevations in serum levels during menstr