A LARGE randomised clinical trial investigated the effects of adding Helicobacter pylori stool antigen (HPSA) testing to colon cancer screening on rates of gastric cancer incidence and mortality.
The trial, conducted between January 1st 2014–September 27th 2018, involved 152,503 participants aged 50–69 years from Changhua County, Taiwan, eligible for biennial faecal immunochemical tests (FIT) for colon cancer screening. Participants were randomly assigned to receive either an invitation for HPSA plus FIT assessment, or FIT screening alone. Primary outcomes were gastric cancer incidence and mortality.
Of 240,000 randomised adults (mean age: 58.1 years; 46.8% female), 63,508 were invited for HPSA + FIT, and 88,995 were invited for FIT alone. Participation rates were higher in the HPSA + FIT group (49.6%) compared to the FIT-alone group (35.7%). Among those with positive HPSA results, 71.4% received antibiotic treatment, with a 91.9% eradication success rate. Adverse effects from antibiotic treatment were minimal, with 2.1% reporting abdominal pain or diarrhoea.
Notably, the authors found that gastric cancer incidence rates were 0.032% in the HPSA + FIT group compared to 0.037% in the FIT-only group, a difference of 0.005 percentage points, which was not statistically significant (P=0.23). Similarly, gastric cancer mortality rates were 0.015% in the HPSA + FIT group and 0.013% in the FIT-only group, showing no significant difference (P=0.57).
While the trial did not find overall reductions in gastric cancer or mortality when HPSA was added to FIT, post hoc analyses, adjusting for factors like participation rates and follow-up length, suggested a potential reduction in gastric cancer incidence. Specifically, after adjustments, those who received the combined screening had a 21% lower rate of gastric cancer (0.79 [95% CI: 0.63–0.98]) but no significant difference in mortality (1.02 [95% CI: 0.73–1.40]).
The findings suggest that adding HPSA testing to colon cancer screening does not significantly reduce gastric cancer rates or mortality. However, the potential benefits of lower cancer incidence after adjustments warrant further investigation.
Ada Enesco, EMJ
Reference
Lee YC et al. Screening for Helicobacter pylori to Prevent Gastric Cancer: A Pragmatic Randomized Clinical Trial. JAMA. 2024; DOI:10.1001/jama.2024.14887.
