Polymorphisms in XRCC1 Gene, Alcohol drinking, and Risk of Colorectal Cancer: a Case-control Study in Jiangsu Province of China

To evaluate the relationship between alcohol drinking, XRCC1 codon 194 and 399 polymorphisms and riskof colorectal cancer, we conducted a case-control study with 315 colorectal cancer cases (105 colon, 210 rectal)and 439 population-based controls in Jiangsu Province of China. The XRCC1 codon 194 and 399 genotypes wereidentified using polymerase chain reaction and restrictrion fragment length polymorphism methods (PCR–RFLP).A structured questionnaire was used to elicit detailed information. Odds ratios (ORs) were estimated with anunconditional logistic model. In this study no significant differences were observed among the studied groupswith regard to the genotype distribution of the XRCC1 codons 194 and 399 and the risk of colorectal cancer didnot appear to be significantly influenced by genotype alone, whereas alcohol consumption showed a positiveassociation (P for trend <0.01). When combined effects of XRCC1 polymorphisms and alcohol consumptionwere analyzed, we found that the 194Trp or 399Gln alleles further increased the colorectal cancer risk due tohigh alcohol intake. These findings support the conclusion that colorectal cancer susceptibility may be alteredby gene-environment interactions.