All gastric malignancies developed in H. pylori-infected patients.
Helicobacter pylori infection is strongly associated with gastric cancer. This relation was examined in a prospective cohort study from Taiwan. The study included 1225 consecutive patients (mean age, 54) who were diagnosed at endoscopy with nonulcer dyspepsia, gastric ulcer, or duodenal ulcer. About half of the patients (618) were H. pylori-positive by histologic examination or urease testing; 59% of infected patients (mainly those with ulcers) received eradication therapy, which was initially successful in most patients. Both infected and noninfected patients underwent surveillance endoscopy about every 2 years.
During a mean follow-up of 6.3 years, seven gastric adenocarcinomas and one lymphoma (a MALToma) were diagnosed in the 618 patients who were H. pylori-positive at baseline, but none were diagnosed in the 607 H. pylori-negative patients. Intestinal metaplasia on baseline gastric biopsy was a significant predictor of cancer. Adenocarcinoma developed both in patients who underwent H. pylori eradication therapy (5 cases) and in those who did not (2 cases).
Comment: In this study, all gastric malignancies developed in H. pylori-infected patients. The results suggest that H. pylori-infected patients with intestinal metaplasia deserve especially close follow-up. Although the numbers were small, the findings also suggest that H. pylori eradication might not prevent cancer unless it is administered sufficiently early in the pathogenesis of the disease. Finally, it is unclear whether these findings can be generalized, because the prevalence of gastric cancer, high in Taiwan, varies considerably across other geographic regions.
— Allan S. Brett, MD
Published in Journal Watch General Medicine May 8, 2007
Hsu P-I et al. Helicobacter pylori infection and the risk of gastric malignancy. Am J Gastroenterol 2007 Apr; 102:725-30.