Gastric histology, serological markers and age as predictors of gastric acid secretion in patients infected with Helicobacter pylori

Effect of smoking on failure of H. pylori therapy and gastric histology in a high gastric cancer risk area of Colombia

It has been proposed that eradication of Helicobacter pylori infection is a sound strategy for gastric cancer prevention. Several factors including smoking have been associated to treatment failure rates. This study aimed to evaluate the smoking effect on the efficacy of H. pylori therapy, as well as on the histological parameters in the gastric mucosa from subjects from a high gastric cancer risk area. Two-hundred-sixty-four Colombian subjects with gastric precancerous lesions who participated in a chemoprevention trial, received anti-H. pylori treatment at baseline and had data recorded on cigarette use, were included in this study. A detailed histopathological assessment of the gastric mucosa was performed in biopsies taken before any intervention. H. pylori eradication was assessed in gastric biopsies at 36 months post-treatment. The overall eradication rate was 52.3%; rates of 41.3% and 57.1% were observed for active-smokers and non-smokers, respectively. Multivariate logistic regression analysis showed that smokers had a 2-fold higher probability of failure in Helicobacter pylori eradication than non-smokers (OR: 2.0; 95% CI: 1.01-3.95). At baseline, active-smokers had a higher score of intestinal metaplasia compared to non-smokers. In the corpus mucosa, active-smokers showed lower scores of H. pylori density, total inflammation, neutrophil infiltration, and mucus depletion than non-smokers. In the antrum, no significant differences were observed between active-smokers and non-smokers. In summary, in patients who smoked, H. pylori treatment was less effective. Smoking cessation may benefit H. pylori eradication rates.

Secondary prevention of gastric cancer

A matter of definitions

Gastric secretion

PURPOSE OF REVIEW

This review summarizes the past year's literature regarding the regulation of gastric exocrine and endocrine secretion.

RECENT FINDINGS

Gastric acid secretion is tightly regulated by overlapping neural, hormonal, paracrine, and intracellular pathways in order to achieve the correct amount of acid secretion required by the specific situation. Too little acid can interfere with the absorption of iron, calcium, vitamin B12, and certain drugs as well as predispose to enteric infection, bacterial overgrowth, and gastric malignancy. Too much acid can induce esophageal, gastric, and duodenal injury. Gastrin, histamine, acetylcholine, and ghrelin stimulate whereas somatostatin, cholecystokinin, atrial natriuretic peptide, and nitric oxide inhibit acid secretion. Most patients infected with Helicobacter pylori manifest a pangastritis and produce less than normal amounts of acid; those with antral predominant gastritis, however, are hypergastrinemic and produce increased amounts of acid. Improved understanding of the channels and receptors that are required for and regulate H+K+-ATPase activity should lead to the development of novel antisecretory agents.

SUMMARY

A better understanding of the pathways regulating gastric secretions should lead to new strategies to prevent and treat a variety of gastric disorders such as gastroesophageal reflux disease, autoimmune gastritis, gastric cancer, and functional dyspepsia.

Sporadic gastric cancer; a complex interaction of genetic and environmental risk factors

Sporadic gastric cancer usually arises against a background of sequential mucosal changes. H. pylori superficial gastritis progresses to atrophy and intestinal metaplasia and then to dysplasia and cancer. A variety of environmental and host genetic factors influence this process and act at different stages in the pathway. Many different combinations of these risk factors may lead to cancer. Interactions also occur between environmental and genetic factors to increase or decrease their ability to influence the precancerous process. Sporadic gastric cancer is thus the consequence of complex combinations and interactions between many environmental and genetic factors.