Investigating global gender gap in lip and oral cavity cancer: A population-based study

Lip and oral cavity cancer (LOC) is typically male predominant, yet in several countries women experience a comparable or even higher burden. Quantifying gender differences in LOC and their social determinants is essential for equitable cancer control.

We analysed Global Burden of Disease 2021 estimates for LOC from 1990 to 2021 across 204 countries and territories. Gender disparities were assessed using the Female-to-Male disability-adjusted life years (DALYs) ratio. Temporal trends were evaluated using estimated annual percentage change (EAPC), and forecasts were generated with exponential smoothing, Bayesian structural time series, and Prophet models. Associations between DALYs ratios and three gender indices, the Global Gender Gap Index (GGGI), Gender Development Index (GDI), and Gender Inequality Index (GII), were examined using Spearman correlation and multivariable generalized linear models.

Globally, the Female-to-Male DALYs ratio for LOC was 0.45 (95% uncertainty interval 0.37-0.57) and increased significantly from 1990 to 2021 (EAPC +0.40%, 95% confidence interval 0.33-0.46). Ratios exceeded 1 in parts of South Asia, the Middle East, and sub-Saharan Africa. The DALYs ratio was negatively correlated with GGGI (ρ = -0.433) and GDI (ρ = -0.562), and positively correlated with GII (ρ = 0.474). In multivariable analyses, only GII remained independently associated with the DALYs ratio (β = 1.702, p < 0.001).

The rising Female-to-Male DALYs ratio for LOC reflects structural and social inequities rather than biological differences. Integrating gender-responsive strategies into cancer prevention, early detection, and policy frameworks is critical, particularly in regions where gender inequities remain entrenched.