SAN DIEGO – Patients with Helicobacter pylori infection face a significantly increased risk for developing colonic neoplasms, according to what is believed to be the largest investigation of the association.
Several studies have suggested that H. pylori infection is a risk factor for colonic neoplasms, but all of them involved relatively small case populations, Dr. Amnon Sonnenberg explained at the annual Digestive Disease Week.
Dr. Sonnenberg, a gastroenterologist with the Portland (Ore.) VA Medical Center, investigated the relationship between H. pylori infection and the presence of colonic neoplasms in 156,269 patients who had undergone both a colonoscopy and an esophagogastroduodenoscopy. Surgical pathology samples from all the patients were stored in an electronic database at the Miraca Research Institute, a specialized gastrointestinal lab that serves private outpatient endoscopy centers throughout the United States. More than 1,500 gastroenterologists contributed to the database between January 2008 and December 2011.
Patients were an average age of 58 years, and 59% were female. Among the total, 16,759 (11%) had H. pylori gastritis on immunochemistry. The prevalence of H. pylori gastritis was 9% in patients without polyps, 11% in patients with hyperplastic polyps, 12% in patients with adenoma, 14% in patients with advanced adenoma, 15% in patients with villous adenoma or polyps with high-grade dysplasia, and 18% in patients with colonic adenocarcinoma.
There was a slight trend for the prevalence of H. pylori to rise with the increasing number, as well as the size, of adenomatous polyps. The prevalence of H. pylori was similar for all colon sites.
Significant associations also were noted between the development of colonic adenoma and the following other types of gastric histopathology: intestinal metaplasia, gastric adenoma, gastric cancer, and gastric lymphoma. Similar but even more significant associations were seen between advanced adenoma and these types of gastric histopathology.
Multivariate logistic regression confirmed that the development of H. pylori gastritis was associated with advanced age, male gender, hyperplastic polyps, adenoma, villous adenoma or high-grade dysplasia, and adenocarcinoma.
"H. pylori gastritis confers an increased risk for colonic neoplasm," concluded Dr. Sonnenberg, who is also professor of medicine in the division of gastroenterology and hepatology at Oregon Health and Science University.
"The risk applies to all types of colonic neoplasms and appears to increase with advancing stage of the neoplasm from hyperplastic and adenomatous polyps to tubulovillous adenoma, adenoma with high-grade dysplasia, and adenocarcinoma. Such risk is not limited to chronic active gastritis but is found in other types of gastric histopathology related to H. pylori, such as gastric intestinal metaplasia, gastric adenoma, gastric lymphoma, and gastric cancer," he said.
Long-term infection with H. pylori "may be related to elevated gastrin levels that may act as a growth factor," he speculated.
Dr. Sonnenberg disclosed having received a research grant from Takeda Pharmaceutical Company. No support was received for this study.