Background: Novel immunotherapies and targeted therapies have transformed melanoma treatment, but the geographic distribution of benefits remains unclear.
Objective: To quantify county-level variation in melanoma mortality declines following the introduction of novel therapies and identify associated patient and health system factors.
Methods: We conducted a repeated cross-sectional ecological study using county-level mortality data from the Surveillance, Epidemiology, and End Results Program. The primary outcome was percent change in age-adjusted melanoma mortality between 2008-2013 and 2019-2023. County characteristics were obtained from the Area Health Resource File, American Hospital Association Survey, Medicare claims, and National Provider Identifier database. Associations were assessed using ordinary least squares regressions.
Results: National melanoma mortality declined 25.6% between 2008-2013 and 2019-2023. Across 751 counties, declines varied widely (median, 23.8%; interquartile range, 7.6% to 35.6%). County population size was the strongest predictor of mortality decline (β = 4.5; 95% confidence interval, 1.6-7.4; P = .002). Had all counties achieved the mortality reductions of the largest counties, 2818 additional deaths could have been prevented.
Limitations: Ecological design and reliance on aggregates limit causal inference and individual-level interpretation.
Conclusions: Population size strongly predicts mortality benefits from novel melanoma therapies, underscoring the importance of strengthening health care infrastructure to reduce geographic disparities.
Keywords: diffusion of innovation; geographic variation; health systems; immunotherapy; melanoma; mortality; oncology; targeted therapy.
Copyright © 2026 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.