Efficacy of Dienogest for Prevention of Endometriosis Recurrence: A Systematic Review and Meta-Analysis

Aim of Study: To evaluate the efficacy of postoperative dienogest for prevention of endometriosis recurrence. Methods: Several databases were used to search for recent studies (i.e., published in 2016-2020). The search keywords included: "dienogest," and "endometr*," Patients who were not treated with dienogest were considered controls. Reviews, comments, animal trials, case reports, abstracts, single-arm studies, low-quality studies, and non-English articles were excluded. The primary outcome of interest was to determine the odds of recurrence in patients who received dienogest compared to controls who were managed expectantly, or offered a substitute hormonal therapy. Secondary outcomes included pain improvement and side effects of received treatment. Results: Included studies comprised three retrospective cohort studies, and two prospective cohort studies. These studies included 608 patients; 216 were managed in the Dienogest Group, while 392 were managed in the Control Group (163 received hormonal suppression, and 228 received no treatment). Overall, the recurrence rate of endometriosis in patients receiving Dienogest was 8/216, i.e., 3.7 events per 100 treated women over a mean duration of 28.5 months, and 1.3 recurrences per 1000 woman-months. On the other hand, the recurrence rate of endometriosis in the Control Group was 69/392 recurrences over a mean duration of 29.3 months, i.e., 17.6 per 100 women (6.0 recurrences per 1000 women-months). Difference in recurrence rates between study groups was statisticallysignificant (X-2=24.3, p<0.001). Reported recurrence rates were significantly less among patients in the Dienogest Group than those in the Control Group, with a pooled estimate of RR = 0.239, and 95% CI: 0.119-0.488. Generally, patients in the Dienogest Group experienced less pain and less side effects than those in the control group. Conclusions: Endometriosis patients who receive dienogest following conservative surgery have a significantly lower rate of recurrence, better pain control, and less side effects than their control counterparts.