Outcomes of women treated with progestin and metformin for atypical endometrial hyperplasia and early endometrial cancer: a systematic review and meta-analysis

Objective Progestin therapy is the recommended fertility-sparing management of atypical endometrial hyperplasia or early-stage endometrial cancer in reproductive-aged women. Our objective was to evaluate disease relapse after progestin and metformin versus progestin therapy alone in patients with endometrial hyperplasia or cancer. Our secondary outcomes were disease remission, clinical pregnancy and live birth rate. Methods A systematic review of the literature was conducted (MEDLINE, Web of Science, Cochrane Library, CINAHL, LILACS, clinicaltrials.gov) from inception to April 2021. Studies of reproductive-aged women with atypical endometrial hyperplasia or early endometrial cancer who received progestin and metformin or progestin alone for fertility-sparing management, were included in the review. Early endometrial cancer was defined as grade 1, stage 1 disease. Exclusion criteria included women with higher grade endometrial cancer and when conservative management was not for fertility-sparing purposes. Data are presented as odds ratios (ORs) and 95% confidence intervals (CIs) with fixed or random effects meta-analysis. Quality scoring was based on the Newcastle-Ottawa and Jadad scales. Results In total, 271 reports were identified and six studies met the inclusion criteria. These studies included 621 women; 241 (38.8%) patients received combined therapy and 380 (61.2%) received progestin therapy alone. Relapse rates were lower for progestin and metformin than for progestin therapy alone (pooled OR 0.46, 95% CI 0.24 to 0.91, p=0.03). The remission rates were not different (pooled OR 1.35, 95% CI 0.91 to 2.00, p=0.14). Women who received progestin and metformin achieved pregnancy and live birth rates similar to those who received progestin therapy only (pooled OR 1.01, 95% CI 0.44 to 2.35, p=0.98; pooled OR 0.46, 95% CI 0.21 to 1.03, p=0.06). Conclusion For reproductive-aged women with atypical endometrial hyperplasia or early endometrial cancer, progestin and metformin therapy compared with progestin therapy alone is associated with lower relapse rates, and similar remission, clinical pregnancy and live birth rates.