Metformin Use Is Associated with Reduced Incidence and Improved Survival of Endometrial Cancer: A Meta-Analysis.

Yun-Liang Tang,Ji-Xiong Xu,Ling-Yan Zhu,Xiang-Xia Zeng,Yu Li,Jiao Yu,Jian-Ying Liu,Jiao Wang,Kai-Xiang Hu

doi:10.1155/2017/5905384

Abstract

Studies have suggested that metformin can potentially decrease the incidence of cancer and improve survival outcomes. However, the association between metformin use and the incidence and survival of endometrial cancer (EC) remains controversial. So, a meta-analysis was performed. An electronic search was conducted using PubMed, EMBASE, and Web of Science. The outcome measures were relative risks (RRs) or hazard ratios (HRs) with 95% confidence intervals (CIs) comparing the EC incidence and survival in patients treated with and without metformin. Eleven studies involving 766,926 participants were included in this study. In the pooled analysis of five studies which evaluated the association of metformin use with the incidence of EC, we found that metformin use was associated with a 13% reduction in EC risk among patients with diabetes (RR = 0.87, 95% CI: 0.80–0.95; p = 0.006). In the pooled analysis of six retrospective cohort studies evaluating the effect of metformin on the survival of EC patients, we found that, relative to nonuse, metformin use significantly improved the survival of EC patients (HR = 0.63, 95% CI: 0.45–0.87; p = 0.006). This study showed that metformin use was significantly associated with a decreased incidence of EC in diabetes and a favorable survival outcome of EC patients.

Highlights

Endometrial cancer (EC) is the most commonly occurring gynecologic malignant tumor of the female reproductive system, and its incidence is increasing worldwide [1, 2]
Of the included studies, adjusted multivariate analyses for the effect of metformin were performed in 9 studies, and unadjusted univariate analyses were performed in 2 studies
In the pooled analysis of five studies which evaluated the association of metformin use with the incidence of EC, we found that metformin use was associated with a 13% reduction in EC risk among patients with diabetes (RR = 0.87, 95% confidence intervals (CIs): 0.80–0.95; p = 0.006)

Summary

Introduction

Endometrial cancer (EC) is the most commonly occurring gynecologic malignant tumor of the female reproductive system, and its incidence is increasing worldwide [1, 2]. Both diabetes and obesity are risk factors which promote the development and progression of EC [3]. Several meta-analyses have shown that metformin use decreased the incidence and improved the survival of a wide range of malignant tumors, such as liver cancer, lung cancer, prostate cancer, and colorectal cancer [9,10,11,12,13,14,15]. Indirect mechanisms may be the inhibition of liver gluconeogenesis, resulting in a decrease in insulin levels and hyperglycemia [17]

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Discussion

Conclusion