Gastric cancer remains one of the most lethal yet preventable malignancies in adults, and the question of whether routine colorectal screening programs could simultaneously address it has long gone unanswered by rigorous economic analysis. A new cost-effectiveness model published in JAMA now provides a quantitative answer that could meaningfully reshape population-level screening protocols.
The analysis compared two strategies: biennial fecal immunochemical testing (FIT) alone versus a co-testing approach that adds a single one-time Helicobacter pylori stool antigen test to standard FIT colorectal screening. By modeling lifetime health outcomes and associated costs across a simulated population, researchers quantified the incremental benefit of detecting and treating H. pylori infection — the dominant causal driver of non-cardia gastric cancer — within an already-established screening infrastructure. The co-testing strategy demonstrated favorable cost-effectiveness ratios, suggesting that the marginal cost of identifying H. pylori carriers and enabling eradication therapy is justified by the downstream reduction in gastric cancer incidence and mortality.
This finding carries significant practical weight. H. pylori infects roughly half the global population and is classified as a Group 1 carcinogen by the WHO, yet it remains systematically undetected in most Western screening programs. The elegance of the co-testing model lies in its low friction — piggybacking on an already-scheduled stool collection requires minimal additional patient burden. However, several limitations deserve attention: cost-effectiveness models are inherently sensitive to underlying assumptions about eradication success rates, re-infection risk, and population H. pylori prevalence, all of which vary substantially by geography and demographics. This analysis likely reflects U.S. or similar high-income country conditions, limiting direct global applicability. Still, for health systems already operating FIT-based colorectal programs, this represents a potentially high-yield, low-cost upgrade worth serious policy consideration.