Use of CA-125 in the diagnosis and management of endometriosis: influence of treatment with danazol.

OBJECTIVE: To compare CA-125 levels in endometriotic women with normal controls. PATIENTS AND METHODS: The level of the oncofetal antigen CA-125 was measured in serum samples taken from 40 women, aged 21 to 33 years. Blood samples for CA-125 from 15 endometriotic women were measured before treatment, during the last 15 days of a 6-month administration of Danazol, and 3 months after treatment, and were compared to findings in 15 women without endometriosis (from whom blood samples were taken only once). RESULTS: The CA-125 levels were significantly higher in patients with endometriosis before treatment as compared with the controls (P < .01). The administration of Danazol significantly reduced the levels of CA-125 (P < .01), and 3 months after treatment the levels of CA-125 remained significantly lower (P < .05) as compared to the respective pretreatment values. CONCLUSION: The results support the view that the determination of CA-125 levels may assist in (a) evaluating women with endometriosis and (b) treatment with Danazol.