Background: Gastric cancer (GC) ranks the second leading cause of cancer-related mortality worldwide. We aimed to clarify the relevance of genetic variants of IL-11 , a hub of various carcinogenic pathways, as well as their interactions with Helicobacter pylori  (H. pylori ) infection in the development of GC.
Methods: A case–control study with 880 GC cases and 900 healthy controls was conducted in a Chinese population. Six tagSNPs were detected by Taqman Allelic Discrimination assay, while H. pylori  status was detected by Typing Detection Kit for Antibody to H. pylori  and serum IL-11  level was measured using ELISA method.
Results: We found that rs1126760 (C vs T: OR=1.39, 95% CIs=1.13–1.70, P =0.002) and rs1126757 (C vs T: OR=0.82, 95% CIs=0.72–0.93, P =0.002) were significantly associated with susceptibility of GC. Even adjusted for Bonferroni correction, the results were still significant (P =0.002×6=0.012). IL-11  rs1126760 was significantly associated with higher serum and expression level of IL-11 , while rs1126757 was significantly associated with lower serum IL-11  level (P <0.001). Significant interaction with H. pylori  infection was identified for rs1126760 (P  for interaction =0.005). Higher expression of the IL-11  gene was significant with development and poor prognosis of GC.
Conclusion: Our study provides strong evidence that genetic variants of the IL-11  gene may interact with H. pylori  infection and contribute to the development of GC. Further studies with larger sample size and functional experiments are needed to validate our findings.
Keywords: gastric cancer, polymorphism, IL-11 , Helicobacter pylori