According to the recent studies, it is shown that the polymorphism of Interleukin 1β gene is associated with the incidence of gastric cancer caused by the Helicobacter pylori infection. Interleukin 1β is a cytokine markedly inhibiting gastric acid secretion. Interleukin 1β production associated with Helicobacter pylori gastric infection may exacerbate mucosal damage including chronic gastritis and atrophic gastritis, may induce eventual neoplasia. Among these Interleukin 1β gene polymorphisms, polymorphisms at -31 portion and -511 portion may associated with these processes, eventually increase the risk of gastric cancer. We investigated the risk of gastric cancer according to the Helicobacter pylori infection and genetic polymorphism of Interleukin 1β in gastric cancer patients.

176 individuals with gastric cancer and 40 healthy controls were analyzed. Each group was divided into two groups whether they infected with Helicobacter pylori or not. DNA was extracted from the peripheral blood in all groups. The PCR-RFLP method was used for investigating the distribution of genotype of C/C, C/T, T/T at -31 portion and -511 portion.

T/T genotype at -511 portion was 19.3% in gastric cancer cases and 10% in controls, which was statistically significant. (P=0.0432) The risk of gastric cancer was increased 4.86 (1.26~18.77) in group which had T/T genotype. In gastric cancer cases, C/C genotype at 31 portion was 27.6% in group with Helicobacter pylori infection and 12.8% in group without infection, which was statistically significant. (P=0.0047) The risk of gastric cancer was increased 4.82 (1.81~12.81) in group which had C/C genotype.

T genotype at -511 portion among the Interleukin 1β genetic polymorphisms may be the risk factor of gastric cancer. And, with Helicobacter pylori infection, C genotype at -31 portion may be the risk factor of gastric cancer.