Correlation of CTLA‐4 polymorphism and the risk of gastric cancer in a Chinese Bai population

Abstract

Cytotoxic T lymphocyte‐associated antigen‐4 (CTLA‐4) is involved in the regulation of immune responses mediated by T cells. This study aimed to explore the correlation between CTLA‐4 gene polymorphisms and the risk of gastric cancer (GC) in the Bai minority population of southwestern China. A total of 422 GC patients and 397 healthy controls (HC) were included in this case–control study. Four single nucleotide polymorphism sites of CTLA‐4 gene (rs231775, rs733618, rs16840252 and rs3087243) were selected and analysed. The results showed a significant difference in the rs733618 loci between GC and HC groups. The frequency of the rs733618 polymorphism ‘TC’ genotype was significantly lower in GC group compared to the HC group [odds ratio (OR), 95% confidence interval (CI): .47 (.35–.63), p < .001]. GC cases with dominant genetic model ‘TC + CC’ had a 47% reduced risk of GC [OR, 95%CI: .53 (.40–.71), p < .001]. Subgroup analyses revealed that the rs733618 ‘TC + CC’ genotype was associated with a lower risk of GC in male patients [OR, 95%CI: .42 (.31–.58), p < .001], those aged ≤60 years old [OR, 95%CI: .27 (.18–.42), p < .001], non‐drinkers [OR, 95%CI: .21 (.13–.33), p < .001], non‐smokers [OR, 95%CI: .38 (.25–.57), p < .001] and individuals without Helicobacter pylori infection [OR, 95%CI: .16 (.10–.26), p < .001]. Further multivariated analyses indicated that individuals with the ‘TC + CC’ rs733618 genotype who were aged ≤60 years old [OR, 95%CI: .42 (.29–.83), p = .032] and had no H. pylori infection [OR, 95%CI: .35 (.28–.76), p = .018] were found to have a protective effect against GC. Additionally, soluble CTLA‐4 were significantly lower in GC patients with ‘TC’ and ‘TC + CC’ genotypes (all p < .05). Our findings suggest that the rs733618 polymorphism of CTLA‐4 gene may play a critical role in the prevention of GC.