Global Burden of Gastrointestinal Cancers Among Adolescents and Young Adults Aged 15–39 Years and Lifestyle‐Associated Risk Factors

BACKGROUND: Gastrointestinal (GI) cancers contribute significantly to the global disease burden, yet their impact on adolescents and young adults (AYAs; ages 15-39) remains understudied. This study aimed to quantify the global burden of GI cancers in AYAs and assess associated risk factors. METHODS: Data on GI cancers, including esophageal, stomach, colorectal, gallbladder and biliary tract, pancreatic, and liver cancers, were retrieved from the Global Burden of Disease (GBD) Study 2021. Socio-demographic index (SDI)-related disparities in incidence and death were analyzed using Spearman correlation and health inequality assessments. Temporal trends were assessed using average annual percentage changes, with future projections by 2045 made using Nordpred models. Risk factors contributing to GI cancer prevalence were evaluated. RESULTS: In 2021, GI cancers accounted for 156 033 new cases and 84 623 deaths among AYAs, with the highest burden observed in East Asia. Age-standardized incidence rate (ASIR) increased, whereas age-standardized death rate (ASDR) decreased with rising SDI levels. Males and individuals aged 35-39 experienced a heavier GI cancer burden. From 1990 to 2021, both ASIR and ASDR for GI cancers declined, with projections indicating further decreases by 2045. The prevalence rate of GI cancers was positively associated with risk factors, including elevated cholesterol, obesity, physical inactivity, tobacco use, and alcohol consumption. CONCLUSION: Despite a global decline in GI cancer burden, substantial disparities remain across regions, sexes, and age groups. Risk factors continue to drive the GI cancer burden. Targeted policies and prevention strategies for high-risk groups are crucial to effectively reduce this burden.