XRCC1 Arg399Gln gene polymorphism and breast cancer risk: a meta-analysis based on case-control studies.

BACKGROUND The Arg399Gln polymorphism in the XRCC1 DNA repair gene is likely to be involved with the development of breast cancer (BC). However, there have been inconsistent reports of association. The objective of this study was to systematically evaluate the published papers. METHODS We performed a meta-analysis of 44 published case-control studies fitting our eligibility criteria. These studies involved XRCC1 Arg399Gln polymorphisms in 20,841 BC cases and 22,688 controls in dominant (GlnGln+ArgGln vs. ArgArg), recessive (GlnGln vs. ArgGln+ArgArg), and co-dominant (GlnGln vs. ArgArg) inheritance models. Analyses of Asian, African and Caucasian ethnic subgroups was also conducted. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. RESULTS Our overall analyses indicated Arg399Gln to be associated with a trend of increased BC risk when using recessive (OR=1.15, 95%CI: 1.05-1.27), and co-dominant models (OR=1.15, 95%CI: 1.04-1.27) to analyze the data. In ethnic subgroups, Arg399Gln significantly increased BC risk in Asians (OR=1.54, 95%CI: 1.18-2.01) when using recessive model analysis, in Africans (OR=1.30, 95%CI: 1.07-1.60) when using dominant model analysis, and in Asians (OR=1.50, 95%CI: 1.15-1.97) and Africans (OR=1.80, 95%CI: 1.08-3.02) when using the co-dominant model analysis. CONCLUSIONS From our meta-analysis of data from 44 publications, we conclude that XRCC1 Arg399Gln allele is a risk factor for the development breast cancer, especially among Asian and African populations.