H. pylori eradication lowers risk of recurring gastric cancer

Last Updated: 2018-03-21

By Gene Emery

(Reuters Health) - Antibiotic therapy to eliminate Helicobacter pylori can prevent tumor recurrence in half the people previously treated for early gastric cancer, but safety questions linger, according to a new randomized trial.

Among 396 volunteers who had endoscopic resection of early gastric cancer or high-grade adenoma, the 194 treated with antibiotics had a rate of new gastric cancer of 7.2% after nearly six years of follow-up, compared to 13.4% among people who received placebo (P=0.03).

At the same time, 48.4% in the antibiotics group showed an improvement in the glandular atrophy grade sampled at the gastric corpus lesser curvature versus just 15.0% with placebo (P<0.001), Dr. Il Ju Choi of the National Cancer Center in Goyang, South Korea, reported online March 21 in The New England Journal of Medicine.

"This is a treatment you give for three weeks and it prevents a cancer 4 or 5 years down the road," said Dr. Paul Oberstein, director of gastrointestinal cancer at NYU Langone's Perlmutter Cancer Center in New York. He was not involved in the research.

"That's significant. That's highly applicable to anyone in any country (at) a high risk of stomach cancer," he told Reuters Health by phone. "I think it will change guidelines."

Survival was not affected by the antibiotic therapy.

Debate over whether eradicating the bacterium halts the carcinogenic process in people with severe chronic atrophic gastritis has prevented widespread adoption of programs to screen and eradicate H. pylori.

The study was done at South Korea's National Cancer Center. Stomach cancer is the most common form of malignant tumor in that country. In Western countries, such tumors are usually found too late to be cured, with a five-year median survival of less than 30%.

In East Asia, where most H. pylori-eradication studies have been done, "125 persons would need to be treated to prevent one case of gastric cancer, so such a strategy is cost-effective in countries with a high incidence of the disease," writes Dr. Peter Malfertheiner of Ludwig Maximilian University of Munich in an editorial accompanying the new study.

"Consideration should also be given to populations with low or intermediate risk," he adds.

In the study, none of the initial gastric cancers or adenomas had spread to the lymph nodes or beyond. None of the volunteers had received previous treatment to eradicate H. pylori.

The treatment, begun within a week after resection, included twice-daily doses of 1,000 mg of amoxicillin, 500 mg of clarithromycin and 10 mg of rabeprazole, a proton-pump inhibitor, for seven days. Placebo therapy included rabeprazole. Everyone stayed on the rabeprazole for four extra weeks to heal any ulcers.

Three months after the beginning of treatment, H. pylori had been eradicated in 80.4% of the antibiotic recipients versus 5.4% of placebo patients.

The treatment did not reduce the odds of developing gastric adenomas.

Dr. Oberstein said today's treatments to eliminate H. pylori "are better than they were" when the study was done. "So we expect the magnitude of benefit would be much better."

There were 11 deaths in the treatment group and six among the placebo recipients (P=0.19). One patient in each group died from gastric cancer.

Mild adverse events were reported by 42% in the antibiotic group and 10% in the placebo group (P<0.001). The treatment produced no serious side effects, although some reported taste alteration, diarrhea and dizziness.

Previous studies of H. pylori eradication have only followed patients for a median of three years or less, according to the researchers.

Dr. Oberstein said the patients in this study need to be followed longer to see if the treatment actually reduces the risk of death, or whether killing off H. pylori in the gut somehow increases the risks of other potentially fatal health problems such as heart disease.

The new study didn't count patients whose secondary cancers were detected within a year after treatment, believing them to be tumors that had been initially missed.

Dr. Choi did not respond to requests for comments.

SOURCE: http://bit.ly/2u6vSvp

New Engl J Med 2018.