The Effect of Hormonal Treatment on Ovarian Endometriomas: A Systematic Review and Meta-Analysis

OBJECTIVE: To evaluate the effect of hormonal suppression of endometriosis on the size of endometriotic ovarian cysts. DATA SOURCES: The authors searched MEDLINE, PubMed, Cochrane Central Register of Controlled Trials, Embase, and ClinicalTrials.gov from January 2012 to December 2022. METHODS OF STUDY SELECTION: We included studies of premenopausal women undergoing hormonal treatment of endometriosis for ≥3 months. The authors excluded studies involving surgical intervention in the follow-up period and those using hormones to prevent endometrioma recurrence after endometriosis surgery. Risk of bias was assessed with the Newcastle-Ottawa Scale and Cochrane Risk of Bias Tool. The protocol was registered in PROSPERO (CRD42022385612). TABULATION, INTEGRATION, AND RESULTS: The primary outcome was the mean change in endometrioma volume, expressed as a percentage, from baseline to at least 6 months. Secondary outcomes were the change in volume at 3 months and analyses by class of hormonal therapy. The authors included 16 studies (15 cohort studies, 1 randomized controlled trial) of 888 patients treated with dienogest (7 studies), other progestins (4), combined hormonal contraceptives (2), and other suppressive therapy (3). Globally, the decrease in endometrioma volume became statistically significant at 6 months with a mean reduction of 55% (95% confidence interval, -40 to -71; 18 treatment groups; 730 patients; p <.001; I2 = 96%). The reduction was the greatest with dienogest and norethindrone acetate plus letrozole, followed by relugolix and leuprolide acetate. The volume reduction was not statistically significant with combined hormonal contraceptives or other progestins. There was high heterogeneity, and studies were at risk of selection bias. CONCLUSION: Hormonal suppression can substantially reduce endometrioma size, but there is uncertainty in the exact reduction patients may experience.