Serum CA-125 levels in women with endometriosis

Forty-two women with laparoscopically-confirmed pelvic endometriosis (assessed according to the American Fertility Society modified classification) had serum levels of the cell-surface antigen CA-125 measured before, during and after medical therapy with nafarelin acetate or danazol combined with follow-up laparoscopic surgery or laparotomy. Serum levels before treatment (39.3 [SE 6.6] U/ml) were elevated above accepted normal levels in many subjects, and these were highly significantly suppressed during medical therapy with both nafarlin and danazol (13.1 [SE 1.5] U/ml at 5 months); t = 3.198; p = 0.002). Levels tended to rise following therapy but a clear correlation between a rise in serum CA-125 and recurrence of disease was not demonstrated. In 3 individuals treated with nafarelin a dramatic rise in serum CA-125 levels was seen after 2 weeks of therapy. This did not correlate with any exacerbation of symptoms or with any rise in serum oestradiol or with pretreatment AFS scoring. Serum CA-125 levels provide a potential approach to the monitoring of treatment and recurrence in a substantial proportion of women with endometriosis, although preliminary evidence suggests that there will be individual exceptions to any broad correlations.