Effect of eradication of Helicobacter pylori on genetic instabilities in gastric intestinal metaplasia

Summary

Background

There is little evidence of changes in genetic variations in gastric intestinal metaplasia (GIM) after the eradication of Helicobacter pylori (H. pylori).

Aim

To investigate the effects of H. pylori eradication on genetic GIM variability in patients with and without gastric cancer in a one-year prospective study.

Methods

We analysed microsatellite instability (MSI) and loss of heterozygosity (LOH) in GIM. Subjects included Gr. A (n = 39): chronic gastritis, and Gr. B (n = 53): intestinal-type early gastric cancer patients who underwent endoscopic mucosal resection (n = 25) and surgical resection (n = 28).

Results

The frequency of incidence of MSI in GIM was 10.3% and 28.3% for Gr. A and Gr. B, respectively. Gr. B showed a significantly (p = 0.03) higher incidence rate than Gr. A for MSI, but not for LOH. The frequency of MSI declined in both groups post-eradication, and patients that were positive for MSI before treatment were negative after H. pylori eradication. Unfortunately, however, GIM scores did not decline significantly post-treatment for either group.

Conclusions

MSI in GIM may be associated with gastric carcinogenesis. H. pylori eradication reduced MSI during the one-year post-treatment period, although no histological improvement in GIM was observed. These changes in MSI may explain the decrease in gastric cancer incidence after the eradication of H. pylori.