Socio-demographic disparities in global trends of lip and oral cavity neoplasms from 1990 to 2021

Oral cancer, the 13th most common globally, is primarily squamous cell carcinoma linked to tobacco, alcohol, and HPV. Despite advances in care, it remains a major health concern due to high mortality and its impact on quality of life. This study analyzed socio-demographic disparities in oral cancer burden using data from 1990 to 2021. We analyzed annual incidence, mortality, and DALYs across 204 countries, using age-standardized rates and the Socio-demographic Index (SDI) to assess development-related impacts. Statistical methods included Kruskal-Wallis tests, linear regression, joinpoint regression for trends, and Exponential Smoothing for forecasts (2022-2030), with analyses conducted in STATA and Python, and p < 0.05 as significant. Incidence was highest in high SDI countries, while mortality and DALYs were highest in low and middle SDI countries (p < 0.001). From 1990 to 2021, incidence increased (AAPC: 0.5-1.0%), while mortality (APC: - 0.5%) and DALYs (APC: - 0.6%) declined in low SDI regions. Significant disparities across SDI categories (p < 0.001) showed incidence rising with socio-demographic development (R² = 0.102, p < 0.001), with high-middle SDI regions bearing the highest mortality and DALYs. These findings highlight the need for awareness, prevention, early detection, and accessible care, especially in lower SDI regions.