Association between single nucleotide polymorphisms in DNA repair genes and the efficacy of radiotherapy in nasopharyngeal carcinoma patients

Introduction: Single nucleotide poly-morphisms (SNPs) in DNA repair genes are mainly correlated with the response to radiotherapy in na-sopharyngeal cancer (NPC). In NPC patients, previous research has stud-ied the association between X-ray re-pair cross-complementing group 1 and 3 (XRCC1 and XRCC3) polymorphisms and radio-therapeutic response. The objective of our study was to test the association between XRCC1 Arg399Gln and XRCC3 Thr241Met polymorphisms and the response to radiotherapy in the NPC Moroccan population.Material and methods: A total of 100 patients with NPC were geno-typed for polymorphisms in XRCC1 and XRCC3 genes.Results: The results revealed that the genotypes and alleles of both SNPs did not show any significant associa-tion with clinical stages (for XRCC1 Arg-399Gln: p [genotype] = 0.559; p [allele] = 0.440) and (for XRCC3 Thr241Met: p [genotype] = 0.638; p [allele] = 0.567). Moreover, in the study of the associa-tion between the polymorphisms and radiotherapy, the response to radia-tion therapy between genotypes and alleles was not statistically significant (for XRCC1 Arg399Gln p [genotype] = 0.583; p [allele] = 0.459) and (for XRCC3 Thr241Met p [genotype] = 0.660; p [allele] = 0.590).Conclusions: The present study sug-gests that XRCC1 Arg399Gln polymor-phism does not have any impact on the radio-therapeutic response in Mo-roccan NPC patients whereas XRCC3 Thr241Met polymorphism may act as a prognostic indicator for NPC patients treated with radiotherapy. However, studies with a larger sample are need-ed to confirm our results.