S1954 Association Between Genetic Variants of DNA Base Excision Repair Genes and Evolution of Precancerous Gastric Lesions

Abstract

Background and aims: The association of Interleukin 1B (IL-1B)-511 polymorphism with gastric cancer is still controversial and the association of IL-1B-511 polymorphism with subtypes of gastric cancer is still largely unknown. We investigated whether the association between IL-1B-511 polymorphism and gastric cancer risk varies by clinically important tumor characteristics and the prognostic value of this polymorphism in a large populationbased case-control study among Chinese. Methods: A population-based case-control study was conducted between 1999 and 2006 in Guangdong Province, China. A total of 1010 gastric cancer patients and 1500 healthy controls were enrolled in this study. Polymorphism in IL-1B-511 was analyzed by polymerase chain reaction-restriction fragment length polymorphism. Comparison of genotype frequencies between cases and controls was assessed by χ2 statistics. Associations between genotypic distributions and clinicopathologic features were analyzed using contingency tables and Pearson's χ2 test. Odds ratios (OR) and 95% confidence intervals (95% CI) were estimated and all statistical tests were two sided. Results: After adjustment for the potential confounding effects of gender and age, compared with the CC genotype, carriers of IL-1B-511 TT genotype had an increased gastric cancer risk (OR= 1.97, 95% CI=1.29-3.01, P=0.0016). In stratified analyses, TT genotype was significantly associated only with intestinal type of gastric cancer (OR=2.14, 95% CI=1.37-3.35, P= 0.0008), but not with the diffuse or mix type of gastric cancer. Moreover, TT genotype was found to be associated with poorly differentiated gastric cancer (OR=2.27, 95% CI=1.433.60, P=0.0005), but not withmoderately or well differentiated gastric cancer. The association between TT genotype and gastric cancer appeared more apparent in the older patients (age≧65) (OR=2.80, 95% CI=1.51-6.77, P=0.0229). IL-1B-511 genotypes were not associated with the prognosis of gastric cancer patients. Conclusions: IL-1B polymorphism influences certain subtypes of gastric cancer according to clinical and pathological features. Understanding the etiologic heterogeneity of gastric cancer may result in improvements in controlling this disorder.