Eliminating the bacterial infection Helicobacter pylori in patients with early gastric cancer may reduce the risk of metachronous disease. In a recent study, eradicating the infection reduced patients' risk of developing a subsequent gastric cancer by almost 50% and, in nearly half of patients, decreased the severity of atrophic gastritis.

Eradicating the bacterial infection Helicobacter pylori (H. pylori) in patients with early gastric cancer halves the risk of a subsequent gastric cancer and decreases the severity of a lesion associated with the disease, according to a study published in The New England Journal of Medicine.

“Gastric cancer is a very important disease worldwide because it's the fourth leading cause of cancer-related death,” explains Richard Peek Jr., MD, a gastroenterologist at Vanderbilt University in Nashville, TN. In addition, H. pylori is the strongest identified risk factor for gastric cancer, infecting more than 4.4 billion people globally at any given time.

Although previous research established a connection between H. pylori and gastric cancer, little evidence from large, prospective, long-term trials on the effect of eradicating H. pylori on disease risk, particularly among high-risk patients, has been collected.

Researchers at the National Cancer Center in Goyang, South Korea, enrolled 470 patients infected with H. pylori who had undergone endoscopic surgery for early gastric cancer or high-grade adenoma. Patients were then assigned to receive either antibiotics to eradicate H. pylori or a placebo.

After a median follow-up of 5.9 years, 7.2% of patients treated for H. pylori had developed metachronous gastric cancer, compared with 13.4% of patients in the placebo group. Additionally, 48.4% of patients in the treatment group had a significant reduction in the severity of atrophic gastritis—a premalignant lesion that occurs during the development of gastric cancer—compared with 15% of patients in the placebo group.

The findings add further evidence that H. pylori plays a leading role in the development of gastric cancer. “I think it really emphasizes the importance of treating H. pylori in persons who are at high risk to develop gastric adenocarcinoma,” says Peek, who was not involved in the study. “It's an important trial with a very strong study design.”

Peek notes, however, that in his practice he already treats patients at high risk for gastric cancer for H. pylori.

“The issue is, what about patients that are not in this high-risk category? Or patients that don't live in areas like Korea where this study was performed, in which the background rates of gastric cancer are so high? Does this study really inform policy or changes in strategies as far as testing and treating?” Peek doesn't think so.

Steven Moss, MD, a gastroenterologist at Brown University in Providence, RI, who was not connected to the research, says that although existing guidelines in the United States and Europe recommend eradicating H. pylori in patients with early gastric cancer, “it's nice to have a very definitive study, which I think has finally conclusively shown that this is the right thing to do.”

Moss thinks the results of the study will have the greatest impact in countries like Korea, where gastric cancer is more common, and on primary care physicians, who see patients infected with H. pylori but may be less aware of its connection to the disease.

Moss is now awaiting the results of population-based screening experiments for H. pylori, which are under way in Taiwan and Japan. “These experiments will give us clues as to what happens in the real world if you take a population-based screening and treating approach to preventing gastric cancer.” –Catherine Caruso

©2018 American Association for Cancer Research.
2018
American Association for Cancer Research.