Genetic Variants of DNA Repair Genes and Prostate Cancer: A Population-Based Study

As part of a population-based case-control study in Shanghai, China, we investigated whether variants in several DNA repair genes, either alone or in conjunction with other risk factors, are associated with prostate cancer risk. Genomic DNA from 162 patients newly diagnosed with prostate cancer and 251 healthy men randomly selected from the population were typed for five nonsynonymous DNA repair markers. We found that the XRCC1 -Arg399Gln AA and the MGMT -Leu84Phe CT+TT genotypes were associated with an increased risk of prostate cancer [odds ratio (OR), 2.18; 95% confidence interval (CI), 0.99-4.81 and OR, 1.99; 95% CI, 1.19-3.34, respectively]. In contrast, XRCC3 -Thr241Met, XPD -Lys751Gln, and MGMT -Ile143Val markers showed no significant associations with risk, although due to the much lower frequency of their variant alleles in this population we cannot rule out small to modest effects. There was a significant interaction between the MGMT-84 marker and insulin resistance ( P interaction = 0.046). Relative to men with the MGMT-84 CC genotype and a low insulin resistance (