Association between codon 399 polymorphism in the X-ray repair cross-complementing group 1 gene and risk of prostate cancer in Asians: A study of 4,479 cases and 4,281 controls

OBJECTIVE The polymorphism in codon 399 of the X-ray repair cross-complementing group 1 (XRCC1) gene may subtly alter structure of DNA repair enzymes and modulate the repair capacity. Impaired DNA repair can lead to the development of cancers such as prostate cancer (PCA). Although the association between the XRCC1 codon 399 polymorphism and PCA risk has been extensively reported, the results have been ambiguous. METHODS We conducted an updated analysis of 18 case-control studies to determine the association between the XRCC1 codon 399 polymorphism and PCA risk. We performed a literature search of the PubMed database to identify all eligible articles that reported this association. Odds ratios (ORs) with 95% confidence intervals (CI) were evaluated to assess the association. RESULTS Significant associations between PCA risk and XRCC1 codon 399 polymorphism were found (such as A-allele vs. G-allele: OR = 1.11, 95% CI = 1.01-1.23). Moreover, subgroup analysis based on ethnicity revealed similar significant associations in Asians (such as AA vs. GG: OR = 1.53, 95% CI = 1.19-1.97). Egger's test did not reveal the presence of a publication bias. CONCLUSIONS Our updated analysis provides evidence for significant association between XRCC1 codon 399 polymorphism and PCA risk. Further carefully designed studies should be performed.