An open randomized comparative study of the effect of goserelin depot and danazol in the treatment of endometriosis. Zoladex Endometriosis Study Team

OBJECTIVE: To compare the efficacy and safety of goserelin depot and danazol for endometriosis. DESIGN: Open, randomized comparative trial. SETTING: Multicenter European academic clinical institutions. PATIENTS: A total of 307 patients with laparoscopically diagnosed endometriosis were randomized to goserelin (n = 204) or danazol (n = 103); 249 patients underwent second look laparoscopy (175 received goserelin and 74 danazol) and were analyzed for efficacy. INTERVENTIONS: A 3.6-mg depot of goserelin monthly subcutaneously or oral danazol 200 mg three times a day administered for 24 weeks. MAIN OUTCOME MEASURES: Efficacy assessments were based on changes in visible deposits at laparoscopy before and after treatment and subjective symptom scores at 4-week intervals during treatment and 8-week intervals after treatment for up to 24 weeks. Safety was assessed by adverse event reporting and clinical laboratory measures. RESULTS: There were similar proportions of symptomatic (73%) and asymptomatic (but infertile) (27%) and comparable distribution of different severity of endometriosis randomized to each treatment. Significantly fewer patients randomized to goserelin (6.4%) withdrew during treatment compared with 20.4% randomized to danazol (P less than 0.05). There were significantly reduced visible deposits of endometriosis found post-treatment (P less than 0.0001) within each group but no differences between the treatments. The mean total subjective symptoms scores remained significantly less than entry at 24 weeks post-treatment (P less than 0.05). Hypoestrogenic side effects were more common in those receiving goserelin, particularly hot flushes, but anabolic/androgenic side effects of weight gain and muscle cramps were more common in those receiving danazol. CONCLUSIONS: The monthly administered 3.6-mg depot preparation of goserelin was highly effective at inducing resolution of endometriotic implants and relieving the symptoms of endometriosis with prevention of their return during 24 weeks follow-up in the majority of patients. However, results were not significantly different from those achieved with danazol 600 mg/d.