Background: 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.
Methods: 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 XRCC1 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.
Results: The XRCC1 genotype distributions of patients with SGC and control participants differed significantly for both the T1915C promoter SNP (P = .047) and the Arg194Trp coding region SNP (P = .037). The polymorphic 1915C allele was significantly less frequent in patients with SGC than in the controls (34% vs 42%; P = .031). Multivariate analysis demonstrated that individuals who had the 1915 polymorphic homozygous CC genotype (OR, 0.4; 95% CI, 0.2-0.9; P = .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; P = .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; P = .036). No findings were significant for the patients who had benign salivary gland tumors.
Conclusions: In this study, the XRCC1 1915C allele was associated with a lower SGC risk, and the XRCC1 194Trp allele was associated with a higher SGC risk.