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

INTRODUCTION: Single nucleotide polymorphisms (SNPs) in DNA repair genes are mainly correlated with the response to radiotherapy in nasopharyngeal cancer (NPC). In NPC patients, previous research has studied the association between X-ray repair 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 genotyped for polymorphisms in XRCC1 and XRCC3 genes. RESULTS: The results revealed that the genotypes and alleles of both SNPs did not show any significant association with clinical stages (for XRCC1 Arg399Gln: 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 association between the polymorphisms and radiotherapy, the response to radiation 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 suggests that XRCC1 Arg399Gln polymorphism does not have any impact on the radio-therapeutic response in Moroccan 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 needed to confirm our results.