Chronic inflammation caused by H. pylori infection in the stomach and GERD in the esophagus are seen as the primary instigators of metaplasia and subsequent adenocarcinoma formation.

Although H. pylori infection can cause gastrointestinal metaplasia, its eradication does not reverse the process.

[1] Bile reflux is an additional pathogenic factor in gastrointestinal metaplasia that can continuously irritate the gastric mucosa.

[1][2] Although it was originally reported that people of East Asian ethnicity with gastric intestinal metaplasia are at increased risk of stomach cancer,[3] it is now clear that gastric intestinal metaplasia is also a risk factor in low-incidence regions like Europe.

[4] Risk factors for progression of gastric intestinal metaplasia to full blown cancer are smoking and family history.