VacA seropositivity is not associated with the development of gastric cancer in a Japanese population.

Abstract

Infection with Helicobacter pylori strains producing vacuolating cytotoxin (VacA) is associated with enhanced gastric mucosal damage and the development of gastric mucosal atrophy. The aim of this study was to investigate whether VacA seropositivity is associated with increasing risk of gastric cancer in Japanese populations which have much higher incidence of gastric cancer than Western populations. Serum sample was collected from 81 patients with gastric cancer and 81 sex- and age-matched endoscopically evaluated control subjects. Histologically, 62 cancers were of the intestinal type and 76 were early gastric cancer. H. pylori and VacA IgG antibodies were assayed by Western blotting using Chiron Diagnostics' Recombinant Immunoblot Assay (RIBAa). VacA seropositivity was 68% (55/81) in patients with gastric cancer and 70% (57/81) in controls. The odds ratio for the risk of gastric cancer in VacA seropositives was 0.89 (95% CI 0.46-1.74). In H. pylori seropositive patients and their control subjects (matched H. pylori-positive controls), VacA seropositivity was the same 80.6% (50/62). The odds ratio for the risk of gastric cancer in H. pylori-positive patients if VacA seropositive was 1.00 (95% CI 0.41-2.44). The mean relative intensity of VacA antibody titre was 3.01+/-0.18 in the 55 VacA seropositive cancer patients and 3.09+/-0.17 in the 57 VacA seropositive control subjects (difference not significant). These results suggest that VacA seropositivity is not associated with increasing risk of gastric cancer in Japanese populations.