Interaction of XRCC1 and XPD Gene Polymorphisms with Lifestyle and Environmental Factors Regarding Susceptibility to Lung Cancer in a High Incidence Population in North East India

Abstract

<b>Background:</b> This study aimed to explore the role of XRCC1 (Arg399Gln) and XPD (Lys751Gln) genepolymorphisms, lifestyle and environmental factors as well as their possible interactions in propensity to developlung cancer in a population with high incidence from North East India. Materials and <br/><b>Methods</b>: A total of 272lung cancer cases and 544 controls were collected and XRCC1 (Arg399Gln) and XPD (Lys751Gln) genotypes wereanalyzed using a polymerase chain reaction based restriction fragment length polymorphism assay. Conditionalmultiple logistic regression analysis was used to calculate adjusted odds ratios and 95% confidence intervalsafter adjusting for confounding factors. <br/><b>Results</b>: The combined Gln/Gln genotype of XRCC1 and XPD genes(OR=2.78, CI=1.05-7.38; p=0.040) was significantly associated with increased risk for lung cancer. Interactionof XRCC1Gln/Gln genotype with exposure of wood combustion (OR=2.56, CI=1.16-5.66; p=0.020), exposure ofcooking oil fumes (OR=3.45, CI=1.39-8.58; p=0.008) and tobacco smoking (OR=2.54, CI=1.21-5.32; p=0.014) andinteraction of XPD with betel quid chewing (OR=2.31, CI=1.23-4.32; p=0.009) and tobacco smoking (OR=2.13,CI=1.12-4.05; p=0.022) were found to be significantly associated with increased risk for lung cancer. <br/><b>Conclusions</b>:Gln/Gln alleles of both XRCC1 and XPD genes appear to amplify the effects of household exposure, smokingand betel quid chewing on lung cancer risk in the study population.