Antidiabetic Medications and the Risk of Endometrial Cancer in Patients.

Background: Recent epidemiological studies suggest that antidiabetic medications (ADMs) may reduce the risks of cancer and cancer mortality among patients with type 2 diabetes. However, data on its effect on endometrial cancer (EC) are unclear. In this systematic review and meta-analysis, we evaluated the association between metformin, sulfonylureas (SUs), insulin, and the risk of EC in patients with diabetes mellitus (DM).

Methods: Studies were identified from PubMed and EMBASE database through October 2017. Observational studies reporting relative risks OR or provided data for their estimation were selected. Summary OR estimates with 95% CIs were estimated using the random-effects model.

Results: Six studies (2 retrospective cohorts and 4 case-control trials) reported 4,739 cases of EC in 510,344 patients with DM. Meta-analysis of observational studies showed no significant association between metformin (n = 6 studies; unadjusted OR 1.15; 95% CI 0.70-1.88; p = 0.59), SUs (unadjusted OR 1.11, 95% CI 0.94-1.32, p = 0.23), or insulin (n = 3 studies; unadjusted OR 1.15; 95% CI 0.93-1.40; p = 0.19) use and risk of developing EC. However, when we do heterogeneity and sensitivity analysis, the use of metformin was associated with an increased incidence of endometrial EC compared to no metformin use (unadjusted OR 1.29; 95% CI 1.16-1.44; p < 0.01).

Conclusions: Our data indicate that metformin, SUs, and insulin did not meaningfully affect the risk of EC. Further investigation is warranted.