Positive correlation between serum and peritoneal fluid CA-125 levels in women with pelvic endometriosis.

CONTEXT AND OBJECTIVE One of the diagnostic markers of endometriosis is CA-125, and elevated levels of this are caused by high concentrations in the ectopic endometrium. The objective of this study was to correlate CA-125 levels in serum and peritoneal fluid from women with and without pelvic endometriosis. DESIGN AND SETTING This was a prospective, cross-sectional, controlled study of consecutive patients undergoing laparoscopy for infertility, pelvic pain or tubal ligation, during early follicular phase, at the university hospital of Faculdade de Medicina de Ribeirão Preto. METHODS Fifty-two patients were divided into two groups: endometriosis group, consisting of 35 patients with biopsy-confirmed pelvic endometriosis, and control group, consisting of 17 patients without endometriosis. CA-125 levels in serum samples and peritoneal fluid were determined by chemiluminescence. RESULTS CA-125 levels in serum and peritoneal fluid were higher in patients with advanced pelvic endometriosis (means of 39.1 +/- 45.8 U/ml versus 10.5 +/- 5.9 U/ml in serum, p < 0.005; 1,469.4 +/- 1,350.4 U/ml versus 888.7 +/- 784.3 U/ml in peritoneal fluid, p < 0.05), and showed a positive correlation between each other (correlation coefficient (r) = 0.4880). Women with more advanced degrees of endometriosis showed higher CA-125 levels in both serum and peritoneal fluid (p = 0.0001). CONCLUSION There is a positive correlation between serum and peritoneal fluid values of CA-125 in women with and without endometriosis, and their levels are higher in peritoneal fluid. Advanced endometriosis is related to higher levels in both serum and peritoneal fluid.