Effect of endoscopic screening for non-cardia gastric cancer: a 12-year report of a population-based randomized trial

BACKGROUND: The benefit of endoscopy for non-cardia gastric cancer (GC) prevention lacks evidence from randomized controlled trials (RCTs). This study aimed to evaluate the effect of endoscopic screening for non-cardia GC through an RCT. METHODS: We conducted a cluster RCT in rural Hua County, northern China (ClinicalTrials.gov, NCT01688908). A total of 668 villages were randomly selected and assigned to either undergo upper gastrointestinal endoscopic screening (screening group) or no screening (control group). Permanent residents aged 45-69 years were enrolled from January 2012 to September 2016. Non-cardia GC mortality between the two groups was compared in intention-to-treat, per-protocol, and subgroup analyses. Poisson regression fitted with generalized estimating equations was used, adjusting for baseline characteristics and accounting for village clustering. RESULTS: The study enrolled 17,104 participants in the screening group, of whom 15,165 (88.7%) underwent endoscopy, and 16,743 in the control group. After a maximum follow-up of 12 years, non-cardia GC mortality was 13.1 per 100,000 person-years in the screening group and 13.5 per 100,000 person-years in the control group. Intention-to-treat analysis showed a 15% lower non-cardia GC mortality in the screening group compared with the control group (adjusted rate ratio [aRR], 0.85 [95% CI: 0.49-1.50]), although the difference was statistically non-significant. In the per-protocol analysis, the aRR for non-cardia GC mortality was 0.70 (95% CI: 0.38-1.29). A subgroup analysis of the screening group restricted to participants who complied with screening protocol and received timely treatment for detected malignancies yielded similar results, with an aRR of 0.66 (95% CI: 0.35-1.22); neither of these analyses reached statistical significance. CONCLUSIONS: In this trial, endoscopic screening was associated with a non-significant reduction in non-cardia GC mortality; larger trials in higher-incidence settings are needed to confirm a benefit.