The effects of post-surgical administration of goserelin plus anastrozole compared to goserelin alone in patients with severe endometriosis: A prospective randomized trial

Abstract

Background: Among patients using GnRH analogues for endometriosis it has been postulated that peripheral and inflammation-induced in-situ aromatization of adrenal androgens are probably the main reasons for the high rates of failure during follow-up. We hypothesized that in cases with premenopausal severe endometriosis, use of a combination of anastrozole and goserelin to achieve almost maximal endocrine blockade of estrogen synthesis after conservative surgery may increase the pain-free interval and reduce the recurrence rates as compared to goserelin alone. Methods: In a prospective randomized trial, we evaluated the efficacy of using either a combination of anastrozole and goserelin for 6 months or goserelin alone for 6 months after conservative surgery for severe endometriosis. The primary outcome measures were the symptom recurrence rates and the impact of treatment on endometriosis-related multidimensional score. The secondary outcome measures were the impact of allocated treatment regimens on menopausal quality of life and on lumbar spine bone mineral density (BMD). Results: When we analyzed the Kaplan-Meier survival curves, we detected a statistically significant advantage of goserelin plus anastrozole as compared to goserelin only, in terms of the median time to detect symptom recurrence (>2.4 versus 1.7 months; log-rank test; P = 0.0089). This statistically significant advantage occurred with a relative risk of 4.3 [95% confidence interval (CI) 1.3-9.8]. Three cases out of 40 recurred in the goserelin plus anastrozole arm (7.5%), whereas we detected recurrences in 14 cases out of 40 cases in the goserelin-only arm (35%.) during the follow-up period of 24 months. Based on these data, the interpretation of Kaplan-Meier curves indicates that at the end of follow-up, 54.7 versus 10.4%, respectively, of the patients were free of recurrence. The mean of the differences in terms of ?baseline-24 months post-medical therapy multidimensional score were statistically significant in favour of goserelin and anastrozole (9.2 ± 2.1 versus 6.7 ± 2.8; paired t-test; P < 0.0001; 95% CI 1.5-4.0). We observed a statistically significant difference in suppression of estradiol concentrations and a significantly greater BMD loss at the end of treatment in the goserelin and anastrozole arm as compared to goserelin-only arm. However, this did not elicit deterioration in menopausal quality of life and the observed bone loss was not significant in terms of ?BMD between the groups at 2 years of treatment withdrawal. Conclusions: Six months of treatment with anastrozole and goserelin as compared to goserelin alone increased the pain-free interval and decreased symptom recurrence rates in patients following surgery for severe endometriosis. Furthermore, menopausal quality of life and BMD at 2 years after medical therapy remained unaffected.