Risk Modulation of Oral Pre Cancer and Cancer with Polymorphisms in XPD and XPG Genes in North Indian Population

Background: Environmental carcinogens cause DNA damages which if not repaired properly, may increase therisk of cancer. The Xerodermapigmentosum group D (XPD) and group G (XPG) genes are essential genes for DNArepair and alteration in DNA repair causes cancer. The present study aimed to evaluate the relationship between XPDand XPG polymorphisms and risk of oral pre cancer and cancer. Methods: Present study genotyped 302 samples oforal diseases and 300 controls for XPD (A/C) and XPG (G/C) polymorphisms with PCR-RFLP method. Results: Ourresult showed that compared to AA genotype frequency of AC and CC genotype for XPD(A/C) polymorphism weresignificantly lower among cases than in control and are associated with decreased risk of oral diseases (OR= 0.621and 0.603 respectively). In contrast with reference to GG genotype the frequency of CC genotype of XPG (G/C) wassignificantly higher in case than in control population (p value=0.004) and found to increase the risk of oral diseases(OR= 2.077). Particularly C allele for XPD A/C polymorphism was found to be associated with decreased risk of Lichenplanus and increased risk of ( OR = 0.470 and 1.541 respectively) oral cancer. While C allele of XPG G/C polymorphismsignificantly increased the risk of Oral Submucous Fibrosis and Leukoplakia (OR= 1.879 and 1.837 respectively) butnot of Lichen planus and oral cancer. In combined genotype analysis from the aforesaid polymorphisms presence of Callele for XPD (A/C) polymorphisms were found to decrease the risk of oral diseases. However, the same C allele wasobserved to increase the chance of having high stage disease (OR= 5.71) with nodal involvement (OR= 6.78) once thecancer been initiated. Conclusion: This work shows association of XPD (A/C), XPG (G/C) polymorphisms with thedevelopment of pre oral cancer as well as oral cancer and its clinical courses.