Association between polymorphisms of the ataxia telangiectasia mutated gene and breast cancer risk: evidence from the current studies

Epidemiological studies have evaluated the association between ataxia telangiectasia mutated (ATM) gene polymorphisms and breast cancer risk. However, published data are still inconclusive. We performed a meta-analysis for the first time, based on currently available evidence, by searching PubMed, ISI Web of Knowledge, and Embase databases to derive a more precise assessment of the relationship. Following the inclusion and exclusion criteria, nine publications were included in this meta-analysis. Of these studies, one had a deviation from the Hardy-Weinberg equilibrium (HWE) at a statistical significance level of 0.01 in controls, and another two had no available data for HWE. We observed that the ATM 5557G > A polymorphism was significantly correlated with breast cancer risk when all studies were pooled into the meta-analysis (recessive model: odds ratio, OR = 0.67; 95% confidence interval (CI) 0.51-0.89). For the ATM IVS38-8T > C polymorphism, no significant association was found in the allele contrast, heterozygote codominant, and dominant models. There were no available data to perform this meta-analysis in the homozygote codominant and recessive models. For the ATM IVS1+19A > T polymorphism, a significant association with breast cancer risk was found in the allele contrast model (C vs. T: OR = 1.60; 95% CI 1.02-2.52). For the IVS34+60G > A polymorphism, no significant association was found in the allele contrast, codominant, dominant, and recessive models. Egger's test did not suggest any evidence of publication bias (P = 0.47 for the recessive model). In conclusion, there is limited evidence to indicate that ATM polymorphisms are associated with increased risk of breast cancer.