IL23R +2199A/C polymorphism is associated with decreased risk of certain subtypes of gastric cancer in Chinese: A case–control study

Introduction: Today, the causal relationship between inflammation and gastric cancer is more widely accepted. Genetic variations in inflammation-related genes especially cytokines and their receptors, were thought to partly determine the outcome of Helicobacter pylori (H. pylori) infection and progression of gastric lesions. Interleukin 23 receptor (IL23R), as a key cytokine receptor gene in the important inflammatory IL-17/IL-23 axis, may contribute to gastric cancer predisposition. Up till now, the associations of IL23R gene polymorphisms with subtypes of gastric cancer are largely unknown. Aims: We investigated whether the association between IL23R +2199 rs10889677 and gastric cancer risk varies by clinical characteristics and the prognostic value of the polymorphism in a case–control study. Methods: A population-based case–control study was conducted in Guangdong. 1010 gastric cancer patients and 800 healthy controls were enrolled. Polymorphism in IL23R was analyzed by PCR-RFLP. Results: Compared with AA, CC carriers of IL23R +2199 polymorphism were associated with protection against gastric cancer (OR = 0.47, 95% CI = 0.31–0.71). In stratified analyses, CC genotype was significantly associated with decreased risk of intestinal type (OR = 0.44, 95% CI = 0.27–0.70), but not with diffuse or mix type of gastric cancer. CC genotype was found to be associated with poorly differentiated (OR = 0.43, 95% CI = 0.26–0.70), but not with moderately or well differentiated gastric cancer. Multivariate analysis showed IL23R +2199A/C variant was not an independent prognostic factor for gastric cancer patients. Conclusion: IL23R 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.