X‐ray repair cross‐complementing group 1 (<i>XRCC1</i>) single‐nucleotide polymorphisms and the risk of salivary gland carcinomas

<jats:title>Abstract</jats:title><jats:sec><jats:title>BACKGROUND.</jats:title><jats:p>X‐ray repair cross complementing group 1 (XRCC1) is important in the repair of single‐strand DNA breaks caused by endogenous oxidative species and exogenous carcinogens.</jats:p></jats:sec><jats:sec><jats:title>METHODS.</jats:title><jats:p>This tertiary cancer center‐based, case‐control association study included 138 patients with salivary gland carcinoma (SGC), 50 patients with benign salivary gland tumors, and a group of 503 cancer‐free control participants. Polymerase chain reaction‐restriction fragment length polymorphism genotyping assays were performed on 6 <jats:italic>XRCC1</jats:italic> single‐nucleotide polymorphisms (SNPs). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated in multivariate logistic regression analyses, and haplotype distributions were estimated.</jats:p></jats:sec><jats:sec><jats:title>RESULTS.</jats:title><jats:p>The <jats:italic>XRCC1</jats:italic> genotype distributions of patients with SGC and control participants differed significantly for both the T1915C promoter SNP (<jats:italic>P</jats:italic> = .047) and the Arg194Trp coding region SNP (<jats:italic>P</jats:italic> = .037). The polymorphic 1915C allele was significantly less frequent in patients with SGC than in the controls (34% vs 42%; <jats:italic>P</jats:italic> = .031). Multivariate analysis demonstrated that individuals who had the 1915 polymorphic homozygous CC genotype (OR, 0.4; 95% CI, 0.2‐0.9; <jats:italic>P</jats:italic> = .017) had a significantly lower risk of SGC, and individuals who had the Arg194Trp heterozygous CT genotype (OR, 1.6; 95% CI, 1.0‐2.6; <jats:italic>P</jats:italic> = .059) had a higher, borderline significant risk. The CGTTGG haplotype was associated with a higher SGC risk (OR, 3.5; 95% CI, 1.1‐11.3; <jats:italic>P</jats:italic> = .036). No findings were significant for the patients who had benign salivary gland tumors.</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS.</jats:title><jats:p>In this study, the <jats:italic>XRCC1</jats:italic> 1915C allele was associated with a lower SGC risk, and the <jats:italic>XRCC1</jats:italic> 194Trp allele was associated with a higher SGC risk. Cancer 2007. © 2007 American Cancer Society.</jats:p></jats:sec>