RCT: H. pylori Screening Added to Fecal Immunochemical Testing Did Not Reduce Gastric Cancer Incidence or Mortality
4 Oct, 2024 | 11:00h | UTCBackground: Gastric cancer is a leading cause of cancer-related mortality worldwide, particularly in East Asia. Helicobacter pylori infection is a well-established risk factor for gastric cancer development. While eradication therapy may prevent gastric cancer, the effectiveness of community-based H. pylori screening on gastric cancer incidence and mortality remains uncertain.
Objective: To determine whether adding H. pylori stool antigen (HPSA) testing to fecal immunochemical test (FIT) screening reduces gastric cancer incidence and mortality compared to FIT screening alone.
Methods: In a pragmatic randomized clinical trial conducted in Changhua County, Taiwan (2014–2018), 152,503 residents aged 50 to 69 years eligible for biennial FIT screening were randomized to receive an invitation for HPSA testing plus FIT (n = 63,508) or FIT alone (n = 88,995). Participants in the HPSA + FIT group with positive HPSA results were offered antibiotic eradication therapy. Primary outcomes were gastric cancer incidence and mortality, assessed via national cancer and death registries.
Results: Participation rates were higher in the HPSA + FIT group (49.6%) than in the FIT-alone group (35.7%). In the HPSA + FIT group, 38.5% tested positive for HPSA, and 71.4% of these received antibiotic treatment, achieving a 91.9% eradication rate. Over a median follow-up of approximately 5 years, gastric cancer incidence did not differ significantly between the HPSA + FIT and FIT-alone groups (0.032% vs 0.037%; mean difference –0.005%; 95% CI, –0.013% to 0.003%; P = .23). Gastric cancer mortality rates were also similar (0.015% vs 0.013%; mean difference 0.002%; 95% CI, –0.004% to 0.007%; P = .57). Adjusted analyses accounting for participation rates, follow-up duration, and baseline characteristics showed a lower gastric cancer incidence in the HPSA + FIT group (RR 0.79; 95% CI, 0.63–0.98; P = .04), but no difference in mortality (RR 1.02; 95% CI, 0.73–1.40; P = .91). Adverse effects from antibiotics were mild, with abdominal pain or diarrhea occurring in 2.1%.
Conclusions: An invitation to HPSA testing combined with FIT did not significantly reduce gastric cancer incidence or mortality compared to FIT alone over a median follow-up of about 5 years. Adjusted analyses suggest a potential reduction in gastric cancer incidence but not mortality when accounting for participation rates and follow-up duration.
Implications for Practice: Adding H. pylori screening to existing FIT programs may not significantly reduce gastric cancer incidence or mortality in the short term, possibly due to low participation rates, incomplete eradication, and limited follow-up. Clinicians should consider these factors when implementing community-based H. pylori screening and weigh the benefits against resource utilization and patient adherence.
Study Strengths and Limitations: Strengths include a large sample size and integration of HPSA testing into an existing FIT screening infrastructure. Limitations encompass differences in participation rates and baseline characteristics between groups, a relatively short follow-up period, and only 71.4% of HPSA-positive participants receiving eradication therapy, which may have reduced the ability to detect significant effects.
Future Research: Longer-term studies with higher participation and eradication rates are needed to assess the long-term benefits of H. pylori screening on gastric cancer incidence and mortality. Research should explore strategies to improve screening uptake and treatment adherence.