Gastric cancer burden from 1990 to 2021, Joinpoint analysis, projections to 2036, and health inequality assessment

Gastric cancer (GC) remains a major global health issue with high incidence and mortality. This study evaluates the global burden and health disparities of GC from 1990 to 2021 and projects trends through 2036, providing evidence for targeted control measures. The data were sourced from the 2021 Global Burden of Disease study, covering the incidence, mortality, disability-adjusted life years, age-standardized incidence rate, age-standardized mortality rate, and age-standardized disability-adjusted life years rate of GC across 204 countries and regions from 1990 to 2021. Joinpoint regression analysis was employed to examine trends between 1990 and 2021, while a Bayesian age-period-cohort model was constructed to assess and project trends up to 2036. Concentration curves and concentration indices were used to examine cross-national relative inequalities in GC burden across sociodemographic index (SDI) levels. Compared to 1990, the number of GC cases and deaths increased in 2021; meanwhile, the age-standardized incidence rate, age-standardized mortality rate, and age-standardized disability-adjusted life years rate declined, respectively. Males consistently faced a higher disease burden across all age groups. The gap between high-SDI and low-SDI countries is narrowing, with underdeveloped countries bearing a relatively heavier burden of stomach cancer. The Bayesian age-period-cohort model predicts a further decline in the global GC burden by 2036. GC remains a substantial global burden, affecting regions and countries worldwide with pronounced geographic, age, and sex-related disparities. Effective interventions – such as Helicobacter pylori prevention and treatment, as well as widespread early GC screening – are crucial for reducing incidence risks and improving survival outcomes.