Susceptibility of XPD and RAD51 genetic variants to carcinoma of urinary bladder in North Indian population

For the present study, two polymorphisms, xeroderma pigmentosum, complementation group D (XPD) Lys751Gln and RAD51 135G/C were studied with regard to bladder cancer. For XPD Lys751Gln polymorphism, an increased risk of bladder cancer was found to be associated with the Gln variant allele (odds ratio [OR]=1.86, 95% confidence interval [CI]=1.27-2.73), on taking AA (Lys/Lys) as the referent genotype. In males, the XPD 751C (Gln) allele was found to be associated with a significantly increased risk (OR=2.33, 95% CI=1.52-3.56). The inhabitants of rural areas showed a significantly increased risk with the XPD Gln allele (OR=2.59, 95% CI=1.46-4.62) when compared with those of urban areas. In smokers (OR=5.30, 95% CI=2.42-11.68), alcohol drinkers (OR=4.33, 95% CI=2.17-8.70), and nonvegetarians (OR=2.21, 95% CI=1.26-3.87), the XPD Gln allele showed a significantly increased risk toward bladder cancer. For RAD51 135G/C polymorphism, no significant difference was observed in the allelic and genotypic frequencies. Even after stratification, no significant association could be seen. After stratifying histopathologically, the RAD51 CC genotype was associted with decreased risk in subjects having superficial stage (OR=0.51, 95% CI=0.27-0.99) and with those having G2 grade (OR=0.24, 95% CI=0.09-0.62) of bladder cancer. XPD polymorphism may be a predisposing factor, but the same cannot be said for RAD51 gene polymorphism.