Abstract 2636: Nonmelanoma skin cancer as a marker of a cancer-prone phenotype: Potential role of DNA repair gene variants

Proceedings: AACR 103rd Annual Meeting 2012‐‐ Mar 31‐Apr 4, 2012; Chicago, IL Purpose: For unknown reasons, nonmelanoma skin cancer (NMSC) is associated with increased risk of other malignancies. This study tested the hypothesis that DNA repair gene variants contribute to the increased cancer risk associated with a personal history of NMSC. Methods: From the parent CLUE II cohort study, established in 1989 in Washington County MD, the study consisted of a cancer-free control group (n=2,296) compared to three mutually exclusive groups of cancer cases ascertained through 2007: 1) Other (non-NMSC) cancer only (n=2,349); 2) NMSC only (n=694); and 3) NMSC plus other cancer (n=577). The frequency of minor alleles in 759 DNA repair single nucleotide polymorphisms (SNPs) was compared in these four groups. Results: Comparing those with both NMSC and other cancer versus those with no cancer, 10 SNPs had additive model p-values<0.01. The two top-ranked SNPs were both within the thymine DNA glycosylase gene (TDG). One was a nonsynonymous coding SNP (rs2888805) (per allele odds ratio (OR) 1.40, 95% confidence interval (CI) 1.16-1.70; p-value=0.0006) and the other was an intronic SNP in high linkage disequilibrium with rs2888805 (rs4135150). Conclusion: The results pinpoint DNA repair genes most likely to contribute to the NMSC cancer-prone phenotype. A promising lead is genetic variants in TDG, important not only in base excision repair but also in regulating the epigenome and gene expression, which may contribute to the NMSC-associated increase in overall cancer risk. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 2636. doi:1538-7445.AM2012-2636