XRCC3 5′-UTR and IVS5-14 polymorphisms and breast cancer susceptibility: a meta-analysis

Published data on the association between XRCC3 5'-UTR and IVS5-14 polymorphisms and breast cancer risk are inconclusive. In order to derive a more precise estimation of the relationship, a meta-analysis was performed. Crude ORs with 95% CIs were used to assess the strength of association between these polymorphisms and breast cancer risk. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. A total of four studies were involved in the meta-analysis with 6,303 cases and 6,563 controls for XRCC3 5'-UTR polymorphism and with 6,270 cases and 6,682 controls for XRCC3 IVS5-14 polymorphism. For XRCC3 5'-UTR A/G polymorphism, significantly elevated breast cancer risk was associated with variant genotype when all studies were pooled into the meta-analysis (AG vs. AA: OR = 1.11, 95% CI = 1.03-1.19; dominant model: OR = 1.09, 95% CI = 1.01-1.17). For XRCC3 IVS5-14 A/G polymorphism, significantly decreased breast cancer risk was associated with variant genotype (GG vs. AA: OR = 0.86, 95% CI = 0.77-0.96). In conclusion, this meta-analysis suggests that the variant G allele of XRCC3 5'-UTR polymorphism is a low-penetrant risk factor for developing breast cancer, while the variant G allele of XRCC3 IVS5-14 polymorphism has a protective effect on breast cancer development.