Risk of gastric cancer development according to the combination of anti–Helicobacter pylori antibody titer and degree of atrophic gastritis.

Abstract

297 Background: Helicobacter pylori is known as the main risk factor for gastric cancer. It is also well known that gastric atrophy which is the result of long-term H. pylori infection induces spontaneous regression of H. pylori infection and such atrophic status with negative H. pylori infection is related with high risk of gastric cancer, as in so called “ABC method”. However the implication of anti- H. pylori antibody titer is not well investigated. This study was designed to identify the risk for gastric cancer according to the combination of level of anti- H. pylori antibody titer and gastric atrophy. Methods: Those who had health checkups including upper endoscopy and serum anti- H. pylori antibody test between 2003 and 2018 were enrolled. Among them, those who had positive results for anti- H. pylori antibody were included in this study and those who had followed up for less than 1 year were excluded. Kimura-Takemoto classification C3 or more was defined as gastric atrophy. Individuals were classified into 4 groups: low B (low titer without atrophy), high B (high titer without atrophy), high C (high titer with atrophy), and low C (low titer with atrophy). Their risks for gastric cancer were compared under adjustment with other risk factors. Results: During median 5.7 years of follow-up, among 28,311 subjects, 231 developed new gastric cancer. Among them, 159 were intestinal type, 68 were diffuse type, and 4 were type-unknown. For intestinal type gastric cancer, high C group and low C group showed significantly high risk compared with low B group (high C: aHR 10.516; 95% CI, 6.485-17.054) (low C: aHR 11.191; 95% CI, 7.096-17.649). However, for diffuse type gastric cancer, high B group showed higher risk compared with low B group (aHR, 1.713; 95% CI, 1.021-2.875). When those two factors were taken separately, grade of atrophy was related with the risk for intestinal type gastric cancer (aHR, 2.047; 95% CI, 1.862-2.251), while the level of anti- H. pylori antibody titer was related with the risk for diffuse type gastric cancer (aHR, 1.158; 95% CI, 1.041-1.288). Conclusions: Among those with current H. pylori infection, high anti- H. pylori antibody titer is related with diffuse type gastric cancer. The risk was prominent especially among those without atrophy. Therefore, those with high level of anti- H. pylori antibody titer need to be considered as high risk group even without atrophy and should be considered as good candidates for H. pylori eradication and intensive screening.