Gonadotrophin releasing hormone agonist (buserelin) in the treatment of endometriosis: changes in the extent of the disease and in CA 125 serum levels after 6-month therapy.

Twenty-two women with endometriosis were treated with the luteinizing hormone-releasing hormone (LHRH) agonist buserelin for 6 months. At second-look laparoscopy the mean score of endometriosis had decreased from 23.1 (SD 17.0) to 17.2 (SD 20.2) (P less than 0.05). CA 125 serum levels decreased from 38.4 (SD 32.2) U/ml at diagnosis to 15.5 (SD 7.0) at second look (P less than 0.005). CA 125 levels correlated at diagnosis with total score of endometriosis (P less than 0.05) and with active score of endometriosis (P less than 0.05), but not with the adhesion score. CA 125 levels were not correlated with endometriosis scores at second look laparoscopy, thus suggesting that mechanisms other than the change in the extent of the disease may be involved in the CA 125 decrease during therapy. CA 125 levels may therefore not be a reliable indicator for monitoring the efficacy of LHRH agonist treatment of endometriosis.