Placebo-controlled study on serum concentrations of CA-125 before and after treatment of endometriosis with danazol or high-dose medroxyprogesterone acetate alone or after surgery.

Serum concentrations of CA-125 were determined in association with 6-month medical (n = 48) or surgical and medical therapy (n = 40) of endometriosis. The concentration of CA-125 was significantly higher in stages III + IV (66.6 +/- 22.0 [standard deviation] U/ml) than in stage I (20.9 +/- 2.3 U/ml) or II (28.4 +/- 2.8 U/ml); in stage II, the concentration was higher than in stage I. Surgical elimination of endometriosis significantly decreased the level of CA-125, as did danazol, but not medroxyprogesterone acetate (MPA), although these drugs were equal in clinical efficacy. The CA-125 changes during hormonal treatment did not correlate with the clinical response. Postoperatively, CA-125 responses to danazol, MPA, or placebo did not differ significantly from each other. During the 6-month follow-up after medication, the CA-125 concentrations tended to increase, especially in danazol-treated women. The determination of CA-125 is useful in estimating the extent of the disease, but it is less valuable in monitoring the treatment effect. The ability of danazol to suppress CA-125 expression emphasizes the specific properties of this drug.