Global Disparities in Melanoma Incidence, Mortality, and Mortality-to-Incidence Ratio: An Analytical Framework Using...

This study aimed to evaluate global disparities in melanoma incidence, mortality, and the mortality-to-incidence ratio (MIR) across countries according to the Human Development Index (HDI) and selected socioeconomic indicators.

We conducted an ecologic study using age-standardized melanoma incidence and mortality data from GLOBOCAN 2022 and socioeconomic variables-including HDI, education indicators, life expectancy, and gross national income-from the World Bank for 165 countries. MIR was calculated as the ratio of mortality to incidence. Socioeconomic variables were categorized into quartiles. Differences across groups were assessed using one-way analysis of variance (ANOVA), and associations were analyzed using Spearman correlation coefficients.

Significant differences in melanoma incidence and mortality were observed across all socioeconomic indicators (ANOVA P < .001). Incidence showed positive correlations with mean years of schooling (ρ = 0.615), HDI (ρ = 0.595), expected years of schooling (ρ = 0.577), gross national income (ρ = 0.532), and life expectancy at birth (ρ = 0.500). Mortality rates were also positively correlated with these variables, although with lower magnitude (ρ range: 0.399-0.548). By contrast, MIR was inversely correlated with all socioeconomic indicators, particularly gross national income (ρ = -0.624) and HDI (ρ = -0.612). MIR values differed significantly across socioeconomic quartiles (ANOVA P < .001).

Melanoma incidence and mortality increase with higher socioeconomic development, whereas MIR decreases, indicating improved survival in more developed settings. These findings highlight substantial global inequalities in melanoma outcomes and underscore the need for strategies aimed at reducing disparities in cancer detection and care worldwide.