The presence of a type of bacteria called Helicobacter pylori in the stomach substantially increases the risk of cancer in the lower portion of the stomach, but may actually lower the risk of cancer in the upper stomach (gastric cardia), a study shows. “Helicobacter pylori… is known to cause gastric and duodenal ulcers and also cancers of the lower part of the stomach,” Dr. Farin Kamangar from the National Cancer Institute, Bethesda, Maryland, told.
“However, the results of our study, as well as some other studies from Western countries, suggest that Helicobacter pylori may protect against cancers that arise at the junction of the stomach and esophagus,” Kamangar added.
In the study, appearing in the October 18th issue of the Journal of the National Cancer Institute, blood samples from 61 patients with gastric cardia cancer and 173 with non-cardia gastric cancer, as well as 234 subjects without cancer matched by age to the cancer patients, were tested for antibodies against Helicobacter pylori.
Patients infected with Helicobacter pylori had a nearly eight-times higher risk of cancer in the lower portion of the stomach and a slightly lower than average risk of developing gastric cardia cancer.
“We know that some other bugs that colonize our guts have beneficial effects in humans,” Kamangar commented. “Helicobacter has co-existed with humans for tens of thousands of years and, therefore, it is plausible that this bug might also have some benefits to humans.”
“There is little doubt that Helicobacter pylori infection needs to be treated in people with gastric and duodenal ulcers,” Kamangar noted. “However, the apparent beneficial effects of Helicobacter pylori caution against its universal eradication. We need to weigh the harms and benefits of (this bacteria) before making decisions to eliminate it.”
SOURCE: Journal of the National Cancer Institute, October 18, 2006.