Global Lip and Oral Cavity Cancer: Analysis of the 2021 Global Burden of Disease Study.

INTRODUCTION AND AIMS: This study aimed to use the Global Burden of Disease (GBD) 2021 Study to analyse the trends in the disease burden of lip and oral cavity cancer (LOCC) at the global, regional, and national levels (1990-2021); to quantify the impacts of population growth, aging, and epidemiological changes on incidence, prevalence, mortality, and disability-adjusted life-years (DALYs); assess health inequalities associated with the Socio-demographic Index (SDI) across countries; and predict the burden trends up to 2050 based on the Bayesian age-period-cohort model (BAPC) model. METHODS: Data from the GBD 2021 Study were included in the age-period-cohort (APC) model to evaluate the effects of age, period, and cohort. Decomposition analysis was used to determine the influencing factors. RESULTS: The global burden of LOCC showed a 'high north, heavy south' bimodal distribution with significant sex differences. Decomposition analyses indicated aging and population growth drive increased morbidity and prevalence, whereas epidemiological changes reduce mortality and DALYs. Absolute inequalities measured using the slope index of inequality (SII) revealed indicating persistent SDI-related absolute inequalities. Concurrently, the concentration index (CI) showed that prevalence remained concentrated in high-SDI settings (CI: 0.26-0.13), whereas mortality and DALYs became increasingly concentrated in low-SDI settings. Projections to 2050 show upward trends in age-standardized incidence rate (ASIR), age-standardized prevalence rate (ASPR), age-standardized mortality rate (ASMR), and age-standardized DALYs rate (ASDR). CONCLUSION: Global LOCC showed increasing incidence and prevalence alongside declining mortality and DALYs from 1990 to 2021, with higher burden in males. Population aging and prevalence increases, whereas epidemiological changes mitigated mortality. BAPC projections indicate increases across all indicators by 2050. SDI-stratified strategies are required: human papillomavirus (HPV) vaccination and screening for high-SDI regions; tobacco control for middle-SDI regions; betel quid regulation and primary care investment for low-SDI regions; and ultraviolet (UV) protection for lip cancer hotspots. CLINICAL TRIAL NUMBER: Not applicable.