Esophageal Cancer Risk Unchanged After H pylori Eradication

Decreased prevalence of Helicobacter pylori infection is not associated with an increased rate of esophageal cancer, based on a multinational cohort study.

This finding suggests that eradication of H pylori is safe with regard to esophageal cancer risk, and eradication campaigns are not contributing to the rising incidence of esophageal adenocarcinoma (EAC) over the past four decades, reported lead author Anna-Klara Wiklund, MD, of Karolinska Institutet, Stockholm, Sweden, and colleagues. “The decreased risk of esophageal adenocarcinoma seen in individuals with H pylori infection is probably explained by the H pylori–induced gastric atrophy, which reduces gastric acid production and thus acidic gastroesophageal reflux, the main risk factor for this tumor,” the investigators wrote in Gastroenterology. “It seems plausible that eradication of H pylori would increase the risk of EAC, although the answer to this question is unknown with the only study on the topic (from our group) having too few cases and too short follow-up.”

That study involved only 11 cases of EAC.

For the present study, Dr Wiklund and colleagues aggregated data from all individuals who had undergone H pylori eradication in Finland, Denmark, Iceland, Norway, and Sweden from 1995 to 2019. The dataset comprised 661,987 such individuals with more than 5 million person-years after eradication therapy, including 550 cases of EAC. Median follow-up time was approximately 8 years, ranging from 1 to 24 years.

Analyzing these data revealed that standardized incidence ratio (SIR) of EAC was not increased after eradication therapy (0.89; 95% CI, 0.82-0.97). In fact, SIR decreased over time after eradication, reaching as low as 0.73 (95% CI, 0.61-0.86) during the follow-up period of 11-24 years. These findings were maintained regardless of age or sex, and within country-by-country analyses.

SIR for esophageal squamous cell carcinoma, which was calculated for comparison, showed no association with eradication therapy (0.99; 95% CI, 0.89-1.11).

“This study found no evidence supporting the hypothesis of a gradually increasing risk of esophageal adenocarcinoma over time after H pylori eradication treatment,” the investigators wrote.

Other risks were detected, including an overall increased SIR of EAC observed among participants with gastroesophageal reflux disease (GERD) and those using long-term proton pump inhibitors (PPIs). These were expected, however, “considering the strong and well-established association with EAC.”

Dr Wiklund and colleagues suggested that more studies are needed to confirm their findings, although the present data provide confidence that H pylori eradication does not raise risk of EAC.

“This is valuable knowledge when considering eradication treatment for individual patients and eradication programs in high-risk populations of gastric cancer,” they wrote. “The results should be generalizable to other high-income countries with low prevalence of H pylori and high incidence of EAC, but studies from other regions with different patterns of these conditions are warranted.”

They also called for more basic research to understand why eradicating H pylori does not lead to an increased risk of EAC. 

The study was supported by Sjoberg Foundation, Nordic Cancer Union, Stockholm County Council, Stockholm Cancer Society. Investigators disclosed no conflicts of interest. 

This article originally appeared on MDedge.com, part of the Medscape Professional Network.