Polymorphism In DNA Repair Genes Affects Survival Of Gastric Cancer Patients

Purpose:DNA repair system is the main defense system of human body.It participates in the repair of DNA damage caused by internal and external environments,and has significant implications for the maintenance of cell stability.The purpose of this study was to investigate the polymorphisms of DNA repair-related genes and their effects on the survival of patients with gastric cancer,including X-ray repair cross-complementing group 1(XRCC1 194C>T),8-hydroxyguanine glycosidase(hOGG1 326C>G)and 06-methylgu-anine DNA methyltransferase(MGMT 84C>T).Methods:To collect 660 patients with histologically confirmed gastric cancer,who were diagnosed between 1999 and 2006.The SNaPshot technique was used to analyze the genotypes.SPSS version 20.0 was used to perform the log-rank tests,Kaplan-Meier,plotschi-square test and Cox regression analyses to analyze the associations between above-mentioned single nucleotide polymorphisms and the survival of gastric cancer patients.Results:The results showed that TNM stage III,tumor>5 cm,lymph node metastasis and distant metastasis were risk factors for the survival of gastric cancer patients(Log-rank P<0.05).The polymorphism of XRCC1 rs1799782 194 C>T was significantly associated with the prognosis of gastric cancer patients.Compared with CC genotype,the median survival time of patients with TC genotype was shortened from 77 months to 48 months(Log-rank P=0.019,HR=1.32,95%CI=1.05-1.66),and the median survival time of patients with TC+TT genotype was also reduced from 77 months to 47 months(Log-rank P=0.042,HR=1.24,95%CI=1.00-1.55),indicating that the TC genotype and TC+TT genotype can lead to poor survival of gastric cancer patients.The polymorphisms of hOGGl rs1052133 326 C>G and MGMT rs12917 84 C>T were not significantly associated with the survival of patients with gastric cancer(Log-rank P>0.05).There was no correlation between the eight genotypes and the survival of gastric cancer patients(Log-rank P>0.05).However,any one of the three genes was mutated,the patient's median survival time will be shortened(the minimum was 39 months and the maximum was 94 months).And no matter how many mutations occurred,the patient's median survival time was still similar.Conclusion:The polymorphism of XRCC1 rs1799782 194 C>T was significantly associated with the survival of patients with gastric cancer.We can use this polymorphism of the XRCC1 gene as a genetic molecular indicator to predict the survival and prognosis of gastric cancer patients.