H-D Wu1, J-J Zhang2, B-J Zhou3. 1. Department of Gastrointestinal Surgery, Second Hospital of Hebei Medical University, Heping Western Road No.215, Shijiazhuang, 050000, Hebei, China. 2. Department of General Practice, Second Hospital of Hebei Medical University, Shijiazhuang, 050000, Hebei, China. 3. Department of Gastrointestinal Surgery, Second Hospital of Hebei Medical University, Heping Western Road No.215, Shijiazhuang, 050000, Hebei, China. bjzhou6600@163.com.
Abstract
OBJECTIVE: Recently, numerous studies have yielded inconsistent results regarding the effect of metformin on esophageal cancer risk in type 2 diabetes mellitus patients. The purpose of this study is to systematically assess this effect using meta-analysis. METHODS: We searched clinical studies on metformin and esophageal cancer risk in PubMed, Embase, and the Cochrane Library. After literature screening, a series of meta-analyses were conducted using RevMan 5.3 software. The pooled hazard ratio (HR) and the corresponding 95% confidence interval (CI) were used as the effect size. RESULTS: Five eligible studies (four cohort studies and one case-control study) were included for our meta-analysis using a random-effect model. The analysis showed that metformin could not reduce esophageal cancer risk in type 2 diabetes mellitus patients (HR 0.88, 95% CI 0.60-1.28, P > 0.05). Subgroup analyses by geographic location showed that metformin significantly reduced esophageal cancer risk in Asian patients with type 2 diabetes mellitus (HR 0.59, 95% CI 0.39-0.91, P = 0.02), without heterogeneity between studies (P = 0.80 and I2 = 0%). CONCLUSIONS: Overall, our systematic review and meta-analysis demonstrate that metformin does not reduce esophageal cancer risk in type 2 diabetes mellitus patients. However, a significant reduction in esophageal cancer risk in Asian populations remains to be clarified.
OBJECTIVE: Recently, numerous studies have yielded inconsistent results regarding the effect of metformin on esophageal cancer risk in type 2 diabetes mellituspatients. The purpose of this study is to systematically assess this effect using meta-analysis. METHODS: We searched clinical studies on metformin and esophageal cancer risk in PubMed, Embase, and the Cochrane Library. After literature screening, a series of meta-analyses were conducted using RevMan 5.3 software. The pooled hazard ratio (HR) and the corresponding 95% confidence interval (CI) were used as the effect size. RESULTS: Five eligible studies (four cohort studies and one case-control study) were included for our meta-analysis using a random-effect model. The analysis showed that metformin could not reduce esophageal cancer risk in type 2 diabetes mellituspatients (HR 0.88, 95% CI 0.60-1.28, P > 0.05). Subgroup analyses by geographic location showed that metformin significantly reduced esophageal cancer risk in Asian patients with type 2 diabetes mellitus (HR 0.59, 95% CI 0.39-0.91, P = 0.02), without heterogeneity between studies (P = 0.80 and I2 = 0%). CONCLUSIONS: Overall, our systematic review and meta-analysis demonstrate that metformin does not reduce esophageal cancer risk in type 2 diabetes mellituspatients. However, a significant reduction in esophageal cancer risk in Asian populations remains to be clarified.
Authors: Paolo Vigneri; Francesco Frasca; Laura Sciacca; Giuseppe Pandini; Riccardo Vigneri Journal: Endocr Relat Cancer Date: 2009-07-20 Impact factor: 5.678