Association between processed meat and red meat consumption and risk for glioma: A meta-analysis from 14 articles

Objective: Epidemiologic studies evaluating the association between processed meat and red meat consumption and glioma risk have produced inconsistent results. Thus, the aim of this study was to conduct a meta-analysis to test the hypothesis that high levels of processed meat consumption could increase the risk for glioma. Methods: Pertinent studies were identified by a search of PubMed and Web of Knowledge up to February 2014. Random-effects model was used to combine the results. Publication bias was estimated using Egger's regression asymmetry test. Results: Fourteen studies involving 3641 cases about processed meat consumption and 3 studies involving 1156 cases about red meat consumption with risk for glioma were included in this metaanalysis. The combined relative risk (RR) of glioma associated with processed meat consumption was 1.25 (95% confidence interval [CI], 1.08-1.45) overall, and 1.28 (95% CI, 1.09-1.50) in the United States. For subgroup of study design, significant association was also found in case-control studies (RR, 1.33; 95% CI, 1.09-1.62), but not in the cohort studies. The association was not significant between red meat consumption and glioma risk (summary RR, 0.89; 95% Cl, 0.71-1.12). No publication biases were found. Conclusions: Our analysis indicated that high levels of processed meat consumption might increase the risk for glioma, and findings are consistent with the hypothesis. No association was found between red meat consumption and glioma risk. (C) 2015 Elsevier Inc. All rights reserved.