XRCC3 Thr241Met polymorphism and breast cancer risk: a meta-analysis.

XRCC3 (X-ray repair complementing defective repair in Chinese hamster cells 3) is a member of the RecA/Rad51-related protein family that participates in homologous recombination, maintaining chromosome stability and participating in DNA repair. Attention has been drawn upon the association of XRCC3 Thr241Met polymorphism with breast cancer risk. The present meta-analysis aims to examine whether XRCC3 Thr241Met polymorphism status is associated with breast cancer risk. Apart from the overall meta-analysis, separate analyses were performed on Chinese and non-Chinese populations, in order to investigate race-specific effects. Eligible articles were identified by a search of MEDLINE bibliographical database for the period up to August 2009. Twenty case-control studies on non-Chinese subjects (19,575 cases and 21,125 controls) and three case-control studies on Chinese subjects (1,216 cases and 1,112 controls) were eligible. Pooled odds ratios (OR) were appropriately derived from fixed-effects or random-effects models. At the overall analysis, the T allele was associated with elevated breast cancer risk mainly following a recessive model (pooled OR = 1.064, 95% CI: 1.007-1.124, fixed effects), given that the effect was more pronounced in homozygous carriers (pooled OR = 1.073, 95% CI: 1.010-1.140, fixed effects). The association seemed confined in non-Chinese populations, once again following a recessive model (pooled OR = 1.072, 95% CI: 1.014-1.133, fixed effects). Concerning Chinese populations, no consistent results were demonstrated. In conclusion, the XRCC3 Thr241Met T allele seems associated with elevated breast cancer risk in non-Chinese subjects. The need for additional studies on Chinese populations seems warranted.