Association between MDM2 rs 2279744 polymorphism and breast cancer susceptibility: A meta-analysis based on 9,788 cases and 11,195 controls

Purpose: Previous studies have suggested associations between MDM2 (mouse double minute 2 homolog) polymorphisms and cancer risk. The aim of this study was to evaluate the relationship between the MDM2 rs 2279744 polymorphism and the susceptibility of breast cancer. Methods: We searched PubMed, Web of Knowledge, Embase, and the Chinese National Knowledge Infrastructure (CNKI) database for case-control studies published up to October 2013 that investigated MDM2 rs 2279744 polymorphism and breast cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of these associations. Results: A total of 19 studies were identified for the meta-analysis, including 9,788 cases and 11,195 controls. The variant P_heterozygote (TG) was associated with breast cancer risk in the overall population (TG vs TT: OR =1.10, 95% CI =1.04-1.17, P=0.001, P=0.23 for P_heterogeneity test). In the subgroup analyses by ethnicity, a significantly increased risk was observed among Asians (G vs T: OR =1.12, 95% CI =1.02-1.23, P=0.02, P_het=0.04; GG vs TT: OR =1.29, 95% CI =1.06-1.56, P=0.01, P_het=0.04; TG vs TT: OR =1.36, 95% CI =1.15-1.60, P=0.0004, P_het=0.45; dominant model TG+GG vs TT: OR =1.21, 95% CI =1.03-1.41, P=0.02, P_het=0.07). However, among Caucasians, rs 2279744 was associated with breast cancer risk in only one genotype (TG vs TT: OR =1.09, 95% CI =1.00-1.18, P=0.04, P_het=0.37). No publication bias was found in the present study. Conclusion: This meta-analysis provides evidence for the association between the MDM2 rs 2279744 polymorphism and breast cancer susceptibility. The results suggest that the MDM2 rs 2279744 polymorphism plays an important role in breast cancer, especially in Asians.