Genetic susceptibility to renal cell carcinoma: The role of DNA double-strand break repair pathway

Alterations in DNA repair genes have been shown to cause a reduction in host DNA repair capacity and may influence host susceptibility to carcinogenesis. The double-strand break repair is a major DNA-repair pathway. This study tested the hypothesis that common sequence variants of the double-strand break pathway genes predispose susceptible individuals to an increased risk for renal cell carcinoma. Toward this end, we evaluated the associations of 13 single-nucleotide polymorphisms in 10 candidate genes involved in the double-strand break pathway with renal cell carcinoma risk in a population-based case-control study that included 326 Caucasian renal cell carcinoma patients and 335 controls. Using the homozygous wild type as the reference group, we observed a significantly increased renal cell carcinoma risk associated with the homozygous variant genotype of NBS1 (rs1805794; odds ratio, 2.13; 95% confidence interval (95% CI), 1.17-3.86). Carrying of at least one copy of the variant XRCC4 allele was also associated with a significantly increased risk (rs1805377; odds ratio, 1.56; 95% CI, 1.08-2.26). Importantly, in pathway analysis, compared with the reference group (1 or less adverse alleles), individuals with two (odds ratio, 1.26; 95% CI, 0.83-1.91), three (odds ratio, 1.00; 95% CI, 0.64-1.56), and more than three adverse alleles (odds ratio, 1.75; 95% CI, 1.03-2.98) were at increased risk for renal cell carcinoma with significant association in subjects carrying more than 3 adverse alleles. Results from this study provide evidence that individuals with a higher number of genetic variations in the DBS repair pathway are at an increased risk for renal cell carcinoma. These findings require further validation in independent populations.