H pylori Eradication Therapy Reduces Noncardia Gastric Cancer Incidence

Helicobacter pylori (H pylori) eradication therapy significantly reduces the incidence of noncardia gastric adenocarcinoma (NCGA) following 8 years, according to study results published in Gastroenterology.

H pylori is a known risk factor for gastric cancer, and studies have shown that H pylori eradication can significantly reduce incidence of NCGA. However, data have been limited in the US regarding these results.

Researchers aimed to investigate the effect of H pylori eradication and incidence of NCGA in a diverse community-based setting in the US.

For the retrospective cohort study, researchers sourced data from Kaiser Permanente Northern California. Individuals in the study were aged 18 years and older and categorized according to their H pylori testing results (active vs prior infection), as well as eradication therapy vs no treatment. The study also consisted of a diverse racial and ethnic population, with 15.9% Asian, 6.6% Black, 20.2% Hispanic, 46.4% non-Hispanic White patients, and 10.9% categorized as other.

Primary outcome was the diagnosis of NCGA. Of 716,567 health plan members, 687,024 (95.9%) had H pylori testing and 29,543 (4.1%) received eradication therapy.

Untreated individuals with a positive H pylori test were found to be at a significantly higher risk for NCGA (HR, 6.07, 95% CI, 4.20-8.76), compared with those who received treatment (HR, 2.68, 95% CI, 1.86-3.86).

Cumulative incidence rates per 10,000 persons at 10 years follow-up for NCGA were significantly higher among individuals positive or untreated for H pylori (IR, 31.0, 16.9-53.5, P <.0001), compared with individuals positive or treated for H pylori (19.7, 14.1-27.0, P <.001). Notably, incidence curves of individuals positive or untreated and positive or treated for H pylori predominately overlapped during the first 7 years of follow-up, with separation starting at 8 years.

Additionally, subdistribution hazard ratios of NCGA among individuals infected with H pylori who received treatment with eradication based on post-treatment serology were similar to those who received treatment without any confirmatory testing (sHR, 3.67; 95% CI, 2.24-6.02 vs sHR, 2.24; 95% CI, 1.43-3.49; P = .10).

Study limitations include individuals who were treated using atypical regimens, which may have misclassified them as untreated.

“H. pylori eradication therapy was associated with a significantly reduced risk of incident NCGA compared with no treatment after 8 years,” the study authors wrote. “The risk among treated individuals became lower than that of the general population after 7-10 years of follow-up, indicating a sustained protective effect against NCGA.”

This article originally appeared on Gastroenterology Advisor