In the management of women diagnosed with endometrial hyperplasia (EH), it is crucial to determine the risk of coexistent cancer. Diabetes mellitus has been recently suggested as a significant risk factor. However, results in this regard are conflicting. Our aim was to assess the association between diabetes mellitus and coexistent cancer in women diagnosed with endometrial hyperplasia. A systematic review and meta-analysis was performed by searching electronic databases from their inception to October 2018 for studies assessing the presence of coexistent cancer after a preoperative diagnosis of endometrial hyperplasia in women stratified for diabetes mellitus. Odds ratio was calculated with 95% confidence interval; a p value <0.05 was considered significant. Twelve retrospective studies with 1579 EH were included. Diabetes mellitus showed significant association with the presence of cancer coexistent with endometrial hyperplasia (OR = 1.96; 95% CI, 1.07-3.60; p = 0.03). Heterogeneity among studies was moderate (I2 = 55%). Funnel plot showed asymmetric distribution of OR values, with the large and accurate studies showing results stronger than small and less accurate one; this finding should exclude a publication bias. In women diagnosed with endometrial hyperplasia, diabetes mellitus is a risk factor for coexistent cancer, and thus may be included in a predictive algorithm for the risk stratification. In women conservatively treated, glycemic control may be required to prevent the risk of progression. Further studies are necessary to confirm the clinical significance of diabetes mellitus in this field.
Keywords: Concurrent cancer; Endometrial cancer; Endometrial intraepithelial neoplasia; Glycemia; Occult cancer; Risk.