Higher Gastric Mucin Secretion and Lower Gastric Acid Output in First-degree Relatives of Gastric Cancer Patients

Abstract

Patients infected by Helicobacter pylori who have first-degree relatives with gastric cancer have an 8-fold increased risk of developing gastric cancer themselves. Mucins are high-molecular-weight glycoproteins that play a cardinal role in the protective mechanism of the gastric epithelium. To study gastric acid and mucin secretion in dyspeptic patients with and without a family history of gastric cancer and H. pylori infection. Twenty-six dyspeptic patients underwent esophago-gastro-duodenoscopy, gastric biopsies, and acid and mucin secretory tests. The sample was divided by family history of gastric cancer and H. pylori status. Patients who were infected by H. pylori had a significantly higher degree of inflammation than those who were not. H. pylori-positive patients with a positive family history had a lower basal and maximal gastric acid output than infected patients with no family history and noninfected controls, and a higher basal and maximal mucin output than infected patients with no family history. MUC5AC was the major mucin species expressed in gastric juice. In patients with relatives with gastric cancer, H. pylori infection is associated with a more severe inflammatory reaction consisting of decreased gastric acid secretion and increased mucin secretion.