Metabolic syndrome and endometrial cancer: a meta-analysis

We performed a systematic review and meta-analysis on the association of metabolic syndrome with endometrial cancer. A systematic literature search of electronic databases (Medline, ISI Web of Knowledge and Scopus) was conducted and complemented by cross-referencing to identify studies published before 31 January 2013. Core items of identified studies were independently extracted by two reviewers, and results were summarized by random effects meta-analysis. We identified six studies, which reported on 3,132 cancer cases. Metabolic syndrome was associated with an increased risk of endometrial cancer (RR: 1.89, 95 % CI 1.34-2.67, P < 0.001), with significant heterogeneity among studies (I-2 = 92 %, P < 0.001), but no indication for publication bias in the Egger's test (P = 0.240). A sensitivity analysis omitting two studies produced no heterogeneity (I-2 = 0 %) and attenuated the association (RR: 1.39, 1.31-1.48, P < 0.001). The risk estimates for any single factor of the syndrome were 2.21 (P < 0.001) for higher values of body mass index and/or waist, 1.81 (P = 0.044) for hyperglycemia, 1.81 (P = 0.024) for higher blood pressure values, and 1.17 (P < 0.001) for high triglyceride levels; there was no significant association with low HDL-cholesterol. Metabolic syndrome is associated with an increased risk of endometrial cancer; among the components of the syndrome, obesity/high waist is that more strongly associated with endometrial cancer.