Polymorphisms of ADPRT Val762Ala and XRCC1 Arg399Glu and risk of breast cancer in Chinese women: a case control analysis.

Adenosine diphosphate ribosyl transferase (ADPRT) and X-ray repair cross-complementing 1 (XRCC1) are two major base excision repair (BER) proteins and act cooperatively in the BER processes. Polymorphisms of ADPRT Val762Ala and XRCC1 Arg399Gln may alter their protein functions and BER activity, and were therefore hypothesized to be associated with breast cancer susceptibility. We examined the contributions of these two polymorphisms to breast cancer susceptibility in a case-control study of 302 breast cancer cases, 221 patients with benign breast disease (BBD) and 639 cancer-free controls in a Chinese population. We found that the variant genotypes of both ADPRT Val762Ala and XRCC1 Arg399Gln were not significantly associated with the risk of breast cancer (adjusted OR 0.87, 95% CI 0.64 to 1.19 for ADPRT Val/Ala + Ala/Ala; adjusted OR 0.82, 95% CI 0.61 to 1.11 for XRCC1 Arg/Gln + Gln/Gln; and adjusted OR 0.70, 95% CI 0.45 to 1.10 for these two combined variant genotypes. Similarly, we did not find any significant associations of these two genotypes with BBD risk. These findings suggest that the ADPRT Val762Ala and XRCC1 Arg399Gln polymorphisms may not play a role in the etiology of breast cancer.