Geographic variation in the impact of novel melanoma therapies on mortality.

Abstract

Novel immunotherapies and targeted therapies have transformed melanoma treatment, but the geographic distribution of benefits remains unclear. To quantify county-level variation in melanoma mortality declines following the introduction of novel therapies and identify associated patient and health system factors. 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. 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. Ecological design and reliance on aggregates limit causal inference and individual-level interpretation. Population size strongly predicts mortality benefits from novel melanoma therapies, underscoring the importance of strengthening health care infrastructure to reduce geographic disparities.