Purpose: Although gastric cancer (GC) has declined in developed countries with improvements in sanitation, changes in diet, and reduced exposure to Helicobacter pylori (Hp), it is a leading cause of cancer-related deaths in many poor countries. We adapted our previously developed empirically-calibrated model of GC to simulate the past population-level dynamics of GC in China, to forecast the expected burden taking into account changing risk factors, and to explore the potential benefit of preventive interventions.

Methods: Using a population model of GC in China, we projected GC incidence between 1985 and 2050 under various scenarios of epidemiologic (risk factor) change and targeted Hp screening and treatment. Data from cross-sectional epidemiologic studies were used to assign risk factor characteristics for birth cohorts born between 1905 and 2034. We simulated the natural history of GC for each birth cohort using an empirically calibrated model capable of reflecting the effects of Hp infection and smoking on disease progression. Cohort-specific model output were aggregated according to the age-structure of the population to generate population-level incidence rates by calendar year.

Results: Incorporating historical trends in Hp prevalence and smoking, age-standardized GC incidence decreased 11% (36.6 to 32.5 per 100,000) between 1985 and 2005, explaining over 50% of the observed decline. Incorporating future expected trends in these risk factors, an additional decline of 28% would be expected between 2005 and 2050, although actual cases would increase by nearly 70% because of population growth and aging. While targeted Hp reduction programs could reduce the expected burden of disease, their population-level benefits would not be realized for several decades. The most effective interventions targeted children with a potential vaccine or universal treatment for Hp (22.4% reduction expected by 2050), or targeted 20-year-olds with once in a lifetime Hp screening/treatment (7.5% reduction expected by 2050).

Conclusions: Despite a continued decline of Hp and smoking, the burden of GC is likely to nearly double over the next few decades in China. Targeted Hp reduction programs could prevent a proportion of these future cancers if implemented now.