Can postoperative GnRH agonist treatment prevent endometriosis recurrence? A meta-analysis

Purpose To investigate whether postoperative GnRH agonist (GnRH-a) treatment can prevent endometriosis recurrence. Methods This meta-analysis searched PubMed, Embase and Cochrane Library for relevant studies published online before June 2015. Seven randomized controlled trials including 328 patients with postoperative GnRH-a treatment and 394 patients in control group were included in the meta-analysis. In the meta-analysis, the recurrence rate of GnRH-a group compared with control group was evaluated with odds ratio (OR) and its 95 % confidence interval (CI). Heterogeneity, small study effect and publication bias were, respectively, assessed using Higgins I-2, sensitivity analysis and funnel plot. Results Postoperative GnRH-a treatment for endometriosis (pooled OR = 0.71; 95 % CI 0.52-0.96) was superior to expectant or placebo treatment in prevention of the recurrence. The recurrence rate decreased significantly in patients who received 6 months GnRH-a treatment (pooled OR = 0.59, 95 % CI 0.38-0.90), whereas no significant difference of recurrence rate existed between patients with 3 months post-surgical GnRH-a therapy and the control group (pooled OR = 0.87, 95 % CI 0.56-1.34). No significant heterogeneity and small study effect were found in the meta-analysis. However, publication bias did existed in the present meta-analysis. Conclusions Longer-term (6 months) postoperative administration of GnRH-a can decrease the recurrence risk of endometriosis, whereas 3 months duration of GnRH-a therapy makes no significant difference in preventing the recurrence of endometriosis. Therefore, instead of a 3 month therapy, the duration of the postoperative administration should be longer enough (6 months) to prevent the recurrence of endometriosis.