Helicobacter pyloriin the Stomach — A Paradox Unmasked

In 1993, a National Institutes of Health Consensus Conference declared infection with Helicobacter pylori to be an important cause of duodenal and gastric ulcers.1 Soon thereafter, the International Agency for Research on Cancer classified H. pylori as a group 1 carcinogen, a definite cause of gastric adenocarcinoma in humans.2 In this issue of the Journal, Hansson and colleagues report that patients with duodenal ulcers have a decreased risk of gastric cancer, whereas those with gastric ulcers have an increased risk.3 Thus, a paradox in the epidemiology of gastric disease is unmasked. The incidence of gastric cancer correlates positively with the . . .