Corruption as an upstream determinant of global cancer outcomes.

e23031 Background: Corruption undermines health systems globally through resource diversion and weakened governance, yet its specific relationship with cancer outcomes has not been systematically quantified. This study evaluated the relationship between national corruption levels and cancer mortality-to-incidence ratios (MIR) globally, with a focus on the mediating factors through which corruption may influence cancer outcomes. Methods: We conducted a global pan-cancer ecological study of 173 countries using GLOBOCAN 2022 data. Corruption was quantified using the 2024 Corruption Perceptions Index (CPI). Univariable and multivariable linear regressions were performed. To evaluate mediation, we applied single-mediator causal mediation analysis using the Imai–Keele–Tingley framework with nonparametric bootstrapping, sequential attenuation modeling, and structural equation modeling. Results: CPI demonstrated a strong inverse association with cancer MIR in univariable analysis (β = −0.00567, p < .001; R² = 0.526). Causal mediation analyses estimated that approximately 94% of CPI's total association with MIR operated through downstream pathways, most prominently Human Development Index (74.1%) and GDP per capita (54.7%). In absolute terms, a 10-point increase in CPI was associated with a 0.059 reduction in MIR. Sequential attenuation modeling similarly demonstrated a 94.4% reduction in the CPI coefficient after adjustment for GDP, UHC, HDI, and health spending. Structural equation modeling estimated that HDI accounted for the largest proportion of the total indirect effect. Conclusions: National corruption levels are strongly associated with cancer outcomes globally, which is largely mediated through economic development and health system capacity. Anti-corruption efforts may therefore function as foundational enablers of effective cancer control by strengthening downstream institutional and economic conditions. Univariable analysis of national health system factors and cancer outcomes. Health System Measure N Beta (95% CI) P value R² Corruption Perceptions Index 173 -0.00567 (-0.0065 to -0.0049) <.001 0.526 GDP per capita (US$) 172 -5.10 × 10⁻⁶ (-5.8×10⁻⁶ to -4.5×10⁻⁶) <.001 0.605 Health spending (% of GDP) 172 -0.022 (-0.030 to -0.018) <.001 0.200 Physicians per 1000 173 -0.066 (-0.070 to -0.054) <.001 0.569 Nurses per 1000 173 -0.030 (-0.031 to -0.025) <.001 0.673 Surgical workforce per 1000 152 -0.0028 (-0.0031 to -0.0022) <.001 0.494 UHC Service Coverage Index 162 -0.0078 (-0.0083 to -0.0068) <.001 0.666 Human Development Index 172 -0.85 (-0.89 to -0.76) <.001 0.782 Gender Inequality Index 152 0.63 (0.57 to 0.70) <.001 0.686 Radiotherapy centers (count) 137 -0.00014 (-0.00024 to -0.00004) .005 0.056 Abbreviations: CI, confidence interval; GDP, gross domestic product; UHC, universal health coverage.