Abstract
Interleukin‐1B and IL‐1 receptor antagonist gene polymorphisms are associated with an increased risk of gastric cancer (GC) in Caucasian populations. However, recent studies could not find any association between IL‐1B‐511T polymorphism and the risk of GC in Asians. We tested for an association between IL‐1 loci polymorphisms with increased gastric mucosal levels of IL‐1β and an increased risk of developing GC in a Korean population. Polymorphisms of IL‐1A‐889, IL‐1B‐31, IL‐1B‐511 and IL‐1RN were genotyped in 434 controls and 234 patients with GC. Mucosal IL‐1β cytokine was measured using an ELISA. The frequencies of IL‐1A, IL‐1B‐511, IL‐1B‐31 and IL‐1RN were not statistically different between controls and all patients with GC. After subclassification of GC, only patients with intestinal‐type GC showed a higher frequency of IL‐1B‐31T homozygotes (OR = 2.2; 95% CI = 1.1–4.3) compared with controls. Risk was also significantly increased in these patients for IL‐1B‐31T homozygotes compared with patients with diffuse‐type GC (OR = 3.4; 95% CI = 1.5–7.7). As in Caucasian populations, linkage disequilibrium between IL‐1B‐31 and IL‐1B‐511 was nearly complete, but the pattern of haplotype related to the risk of GC (IL‐1B‐31T/IL‐1B‐511C) was opposite (IL‐1B‐511T/IL‐1B‐31C). Mucosal IL‐1β levels in H. pylori‐infected GC patients were higher in patients homozygous for IL‐1B‐31T compared with IL‐1B‐31C/T and IL‐1B‐31C/C. Thus, the combined effects of H. pylori infection and IL‐1B‐31T/IL‐1B‐511C polymorphisms with enhanced mucosal IL‐1β production contributed to the development of intestinal‐type GC in this Korean population. © 2004 Wiley‐Liss, Inc.