A population-based study of DNA repair gene variants in relation to nonmelanoma skin cancer as a marker of a cancer-prone phenotype
Menée sur trois groupes de patients atteints de cancer (3 620 au total) et 2 296 témoins, cette étude identifie des variants de gènes de réparation de l'ADN en association avec un risque accru de second cancer chez les patients atteints d'un cancer de la peau autre qu'un mélanome
For unknown reasons, nonmelanoma skin cancer (NMSC) is associated with increased risk of other malignancies. Focusing solely on DNA repair or epair-related genes, this study tested the hypothesis that DNA repair gene variants contribute to the increased cancer risk associated with a personal history of NMSC. 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. Comparing those with both NMSC and other cancer versus those with no cancer, 10 SNPs had allelic trend 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). None of the associations had a p-value <6.6x10-5, the threshold for statistical significance after correcting for multiple comparisons. 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.
http://carcin.oxfordjournals.org/content/early/2012/05/11/carcin.bgs170.abstract 2012