The Significant Contribution of Interleukin-16 Genotypes, Smoking, Alcohol Drinking, and Helicobacter Pylori Infection to Gastric Cancer

Background/Aim: Elevated serum interleukin-16 (IL-16) levels have been reported in gastric cancer (GC) tissues; however, the role of IL-16 genotypes in GC susceptibility remains largely unexplored. This study aimed to investigate the contribution of IL-16 genotypes to GC susceptibility and to assess their interactions with smoking, alcohol drinking, and Helicobacter pylori (H. pylori) infection.Materials and Methods: Polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP) methodology was employed to determine IL-16 rs4778889, rs11556218, and rs4072111 genotypic characteristics in 161 patients with GC and 483 controls.Results: Significant differences were observed in the distribution of genotypic (p=0.0009) and allelic (p=0.0002) frequencies of IL-16 rs11556218 among cases and controls. Specifically, the frequencies of TG and GG genotypes of IL -16 rs11556218 were 37.3% and 6.8% among patients with GC, respectively, which were higher than those among the controls (26.7% and 2.7%). In contrast, no significant differences were found concerning IL-16 rs4778889 or rs4072111. Notably, individuals with IL-16 rs11556218 TT genotypes exhibited significant protective effects against GC when exposed to risk factors, such as smoking, alcohol drinking, and H. pylori infection. Conclusion: IL-16 rs11556218 T allele was associated with reduced susceptibility to GC. Furthermore, carriers of the TT genotype showed protection against GC risk factors, including smoking, alcohol drinking, and H. pylori infection. These findings provide valuable insights into the potential role of IL-16 genotypes in GC development and their interactions with lifestyle and infectious factors.