Abstract
Brain and central nervous system (CNS) cancers are a major cause of cancer-related mortality and morbidity among adolescents and young adults (AYAs) aged 15-39, presenting significant global health challenges despite advances in treatment. This study assesses the global burden and future trends of CNS cancers in AYAs using data from the Global Burden of Disease (GBD) 2021 database. Data on incidence, mortality, and disability-adjusted life years (DALYs) from 1990 to 2021 were analyzed for 204 countries and territories. Age-standardized rates for incidence (ASIR), mortality (ASMR), and DALYs (ASDR) were calculated, with temporal trends assessed using Joinpoint regression and future projections estimated using the Bayesian Age-Period-Cohort (BAPC) model. Disparities were evaluated using the Socio-Demographic Index (SDI), a composite measure of income, education, and fertility rates. In 2021, global CNS cancer incidence among AYAs was 57,645 cases, with a prevalence of 271,770. The ASIR was 1.92 per 100,000, the ASMR 0.95 per 100,000, and DALYs totaled 1,744,650. High-SDI regions reported higher ASIR but lower ASMR and ASDR. By 2040, case numbers are projected to rise, while age-standardized rates may stabilize or decline. This study highlights significant global disparities in CNS cancer burden, calling for investments in cancer registries, equitable healthcare access, and tailored prevention and treatment strategies.