Global, Regional, and National Trends in Lip and Oral Cavity Cancer Incidence From 1990 to 2021 and Projection to 2040: A Systematic Analysis

BACKGROUND: Lip and oral cavity cancer (LOCC) represents a significant global health burden, with varying incidence rates across regions and populations. Understanding these trends is crucial for effective resource allocation and the development of targeted public health interventions. METHODS: We extracted LOCC incidence data from the GBD 2021 study, covering the period from 1990 to 2021. Age-standardized incidence rates (ASRs) were calculated, and temporal trends were assessed across geographical and socioeconomic strata. The Estimated Annual Percentage Change (EAPC) was calculated to assess temporal trends. A Bayesian age-period-cohort (BAPC) model was applied to predict future incidence rates up to 2040 under the scenario of unchanged population-level risk-factor exposure and no large-scale public-health interventions. RESULTS: Global new LOCC cases reached 421.6 thousand in 2021, up by 142.2% relative to 1990; the global ASR increased 0.40% annually to 4.9 per 100,000. Regional disparities were striking: South Asia, Australasia and Eastern Europe bore the highest ASRs, while several high-income countries showed decreasing incidence. Females demonstrated a higher EAPC of ASR compared with males. National-level trends could not be directly predicted by sociodemographic index. In the absence of effective interventions, the global ASR is projected to rise to 5.26 per 100,000 and new cases to 610.1 thousand by 2040. CONCLUSION: The global incidence of LOCC has increased significantly over the past three decades, with substantial regional variations. Effective prevention and early detection strategies are crucial for reducing the incidence and improving outcomes for LOCC globally.