Gonadotropin-releasing hormone analogues for the treatment of endometriosis: long-term follow-up

OBJECTIVE: To determine the long-term recurrence rate of endometriosis after treatment with gonadotropin-releasing hormone analogues (GnRH-a). DESIGN: A historical prospective study. SETTING: Royal Free Hospital, London, a tertiary referral center for the treatment of endometriosis. PATIENTS: One hundred thirty patients with endometriosis had treatment with GnRH-a buserelin acetate, goserelin, and nafarelin acetate between the years 1985 and 1987. Patients no longer being followed in the gynecology clinic were sent a questionnaire to determine their state of health. Information was also requested from the patient's general practitioner. MAIN OUTCOME MEASURES: The cumulative recurrence rate for the fifth year after treatment ended was 53.4%. RESULTS: Patients with a higher disease stage at the outset were more likely to experience recurrence and experience it earlier than patients with minimal disease. Fifth-year recurrence rates were 36.9% for minimal disease and 74.4% for severe disease. The change in endometriosis stage classification scores at second-look laparoscopy for those patients whose disease recurred after treatment was not significantly different from those whose disease did not recur during the study period. CONCLUSIONS: Patients with endometriosis treated with GnRH-a are highly likely to suffer a recurrence of their disease, particularly if their disease is severe at the outset.