Levonorgestrel-releasing intrauterine system vs oral progestins for non-atypical endometrial hyperplasia: a systematic review and metaanalysis of randomized trials

We sought to evaluate the therapeutic efficacy of levonorgestrel-releasing intrauterine system (LNG-IUS) with oral progestins for treatment of non-atypical endometrial hyperplasia (EH). Searches were conducted on PubMed, SCOPUS, and CENTRAL databases to August 2014, and reference lists of relevant articles were screened. The search was limited to articles conducted on human beings and females. The PRISMA Statement was followed. Seven randomized controlled trials (n = 766 women) were included. Main outcome measures were the therapeutic effect rate (histological response) after 3, 6, 12, and 24 months of treatment; rate of irregular vaginal bleeding; and the hysterectomy rate per woman randomized. The Cochrane Collaboration risk of bias tool was used for quality assessment. Metaanalysis was performed with fixed effects model. LNG-IUS achieved a highly significant therapeutic response rate compared with oral progestins after 3 months of treatment (odds ratio [OR], 2.30; 95% confidence interval [CI], 1.39-3.82; P = .001, 5 trials, I(2) = 0%, n = 376), after 6 months of treatment (OR, 3.16; 95% CI, 1.84-5.45; P < .00001, 4 trials, I(2) = 0%, n = 397), after 12 months of treatment (OR, 5.73; 95% CI, 2.67-12.33; P < .00001, 2 trials, I(2) = 0%, n = 224), and after 24 months of treatment (OR, 7.46; 95% CI, 2.55-21.78; P = .0002, 1 trial, n = 104). Subgroup analysis showed evidence of highly significant therapeutic response following LNG-IUS compared with oral progestins for non-atypical simple as well as complex EH (OR, 2.51; 95% CI, 1.14-5.53; P = .02, 6 trials, I(2) = 0%, n = 290; and OR, 3.31; 95% CI, 1.62-6.74; P = .001, 4 trials, I(2) = 0%, n = 216, respectively). Compared with oral progestins, LNG-IUS achieved significantly fewer hysterectomies (OR, 0.26; 95% CI, 0.15-0.45; P < .00001, 3 trials, n = 362, I² = 42%). No difference was observed in the rate of irregular vaginal bleeding between both groups (OR, 1.12; 95% CI, 0.54-2.32; P = .76, 2 trials, n = 207, I² = 77%). Funnel plot analysis was not performed because of the relatively small number of included studies. For treatment of non-atypical EH, LNG-IUS achieves higher therapeutic effect rates and lower hysterectomy rates than oral progestins and should be offered as an alternative to oral progestins in these cases.