XRCC1 Gene Polymorphism, Clinicopathological Characteristics and Stomach Cancer Survival in Thailand

Background: Stomach cancer is one of leading causes of death worldwide. In Thailand, the incidence andmortality of stomach cancer are in the top ten for cancers. Effects of DNA repair gene X-ray repair crosscomplementary protein 1 (XRCC1) polymorphisms and clinicopathological characteristics on survival of stomachcancer in Thailand have not been previously reported. The aim of this study was to investigate the effects of XRCC1gene and clinicopathological characteristics on survival of stomach cancer patients in Thailand. Materials and
Methods: Data and blood samples were collected from 101 newly diagnosed stomach cancer cases pathologicallyconfirmed and recruited during 2002 to 2006 and followed-up for vital status until 31 October 2012. Genotypeanalysis was performed using real-time PCR-HRM. The data were analyzed using the Kaplan-Meier methodto yield cumulative survival curve, log-rank test to assess statistical difference of survival and Cox proportionalhazard models to estimate adjusted hazard ratio.
Results: The total followed-up times were 2,070 person-months,and the mortality rate was 4.3 per 100 person-months. The median survival time after diagnosis was 8.07 months.The cumulative 1-, 3-, 5-years survival rates were 40.4%, 15.2 % and 10.1 % respectively. After adjustment,tumour stage were associated with an increased risk of death (p= 0.036). The XRCC1 Gln339Arg, Arg/Arghomozygote was also associated with increased risk but statistically this was non-significant.
Conclusions: Inaddition to tumour stage, which is an important prognostic factor affecting to the survival of stomach cancerpatients, the genetic variant Gln339Arg in XRCC1 may non-significantly contribute to risk of stomach cancerdeath among Thai people. Larger studies with different populations are need to verify ours findings.