Tumor necrosis factor alpha-238G/A polymorphism and risk of breast cancer An update by meta-analysis

Background: The association between the tumor necrosis factor-alpha gene (TNF-alpha) -238G/A polymorphism and the breast cancer has been analyzed in several studies, but the results have been inconclusive. We then performed a meta-analysis to get a precise estimation of the association. Methods: Eight case-control studies with a total of 37,257 cases and 39,564 controls were identified by searching the ISI Web of Knowledge database and the PubMed database up to August 2014. Results: Overall, no association was found between TNF-alpha-238G/A polymorphism and breast cancer in any of genetic model (additive model OR= 1.06, 95% CI: 0.94-1.21, P-heterogeneity=.02; homozygous model OR= 1.04, 95% CI: 0.83-1.30, P-heterogeneity =.98; dominant model OR= 1.06, 95% CI: 0.92-1.21, P-heterogeneity=.01; recessive model OR= 1.04, 95% CI: 0.83-1.30, P-heterogeneity=.98). Furthermore, no significant association was identified when stratified by ethnicity (Caucasian, Asian). Conclusion: This meta-analysis indicated that the TNF-alpha-238G/A polymorphism is not associated with breast cancer risk in the overall population.