UPDATED with comments January 31, 2020 // Treatment of Helicobacter pylori infection in patients with a family history of gastric cancer more than halves their risk of developing gastric cancer, according to the results of a large-scale, long-term randomized trial from South Korea.
Moreover, successful eradication of the infection reduced the risk of gastric cancer by 73% compared with patients in whom the infection persists, the study also shows.
The study was published online today in the New England Journal of Medicine.
"A family history of gastric cancer in a first-degree relative is associated with double to triple the risk of gastric cancer," note Il Ju Choi, MD, PhD, National Cancer Center, Goyang, South Korea, and colleagues.
Eradication of H pylori reduces this risk, they conclude.
"Our data emphasize that eradication success should be confirmed, as the 'test–treat–test' approach recommends," they suggest.
These data may not apply to Western populations, cautioned Alexander C. Ford, MBChB, MD, professor of gastroenterology at the Leeds Institute of Medical Research at St. James's, University of Leeds, UK, who was approached for comment.
"It is important to understand that Korea is a high-risk country for gastric cancer (as are China and Japan), so while these data add to the evidence for adopting a search and eradicate program in countries at high risk of gastric cancer, the evidence would not apply to Western populations (unless they had migrated from an area with a high risk of gastric cancer)," he said.
The study involved 1676 participants in the modified intention-to-treat analysis (832 assigned to the treatment group, 844 randomly assigned to placebo).
"Participants were eligible if they were 40 to 65 years of age and if they had confirmed H pylori infection and at least one first-degree relative with gastric cancer," investigators note.
Patients randomly assigned to the treatment group received amoxicillin 1000 mg, clarithromycin 500 mg, and lansoprazole 30 mg twice a day for 7 days. Surveillance endoscopies were carried out every 2 years.
At study endpoint, 1.2% of patients in the treatment group had developed gastric cancer compared with 2.7% of those randomly assigned to placebo (P = .03), investigators report.
"All cases of gastric cancer were detected by means of the surveillance endoscopies," they add, and almost all cases (90.9%) were stage 1 disease; the remainder were stage 2.
During the follow-up interval, 1587 patients were evaluated for their H pylori eradication status, and eradication was confirmed in 70.1% of the treatment group vs 7.1% of placebo controls.
Infection persisted in the remaining 979 participants. Among this group of patients, 2.9% developed gastric cancer compared with only 0.8% of those in whom the infection had been eradicated (hazard ratio, 0.27).
"The incidence of gastric cancer among participants in the treatment group who had persistent infection was similar to the incidence among participants in the placebo group with persistent infection," researchers confirm.
On the other hand, the group observed no significant difference in overall survival between the two groups, nor did the causes of death differ between the two groups.
Drug-related adverse events were more common in the treatment group but were predominantly mild.
Of note, treatment of H pylori did not lower the incidence of gastric adenoma compared with placebo, suggesting that the adenoma–carcinoma sequence is not the pathway activated by H pylori in the development of gastric cancer, the authors indicate.
Editor's note: This article has been updated with comments from an outside expert.
The study was supported by grants from the National Cancer Center, South Korea. The authors have disclosed no relevant financial relationships.
N Engl J Med. Published online January 30, 2020. Abstract
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