Researchers from the Kure Kyosai Hospital, and the Fukuoka University School of Medicine, in Japan, assessed the association between Helicobacter pylori infection and the development of gastric cancer.
They prospectively studied 1526 Japanese patients who had duodenal ulcers, gastric ulcers, gastric hyperplasia, or non-ulcer dyspepsia at the time of enrollment. Of these, 1246 had H. pylori infection and 280 did not.
The mean follow-up period was 7.8 years.
Patients underwent endoscopy with biopsy at enrollment, and then between 1 and 3 years after enrollment.
H. pylori infection was assessed by histologic examination, serologic testing, and rapid urease tests. It was defined by a positive result on any of these tests.
Gastric cancers developed in 36 (2.9%) of the infected, and none of the uninfected patients.
| Characteristics of H. pylori-infected patients at increased risk:|
- severe gastric atrophy
- corpus-predominant gastritis
- intestinal metaplasia
- non-ulcer dyspepsia
- gastric ulcers
|New England Journal of Medicine|
There were 23 intestinal-type and 13 diffuse-type cancers.
Among the patients with H. pylori infection, those with severe gastric atrophy, corpus-predominant gastritis, and intestinal metaplasia were at significantly higher risk for gastric cancer.
The researchers detected gastric cancers in 4.7% of the 445 patients with non-ulcer dyspepsia, 3.4% of the 297 with gastric ulcers, 2.2% of the 229 with gastric hyperplastic polyps, and none of the 275 with duodenal ulcers.
Dr Naomi Uemura, of the Department of Gastroenterology at the Kure Kyosai Hospital, concluded on behalf of the team, "Gastric cancer develops in persons infected with H. pylori, but not in uninfected persons.
"Those with histologic findings of severe gastric atrophy, corpus-predominant gastritis, or intestinal metaplasia are at increased risk.
"Persons with H. pylori infection and non-ulcer dyspepsia, gastric ulcers, or gastric hyperplastic polyps are also at risk. However, those with duodenal ulcers are not."