Impact of Medicaid expansion on five-year mortality among patients with melanoma in the United States.

Abstract

e21603 Background: Melanoma survival depends on early diagnosis and timely access to definitive surgery and modern systemic therapies, including immune checkpoint inhibitors. Insurance-related barriers may therefore exert an ample influence on outcomes in melanoma. While Medicaid expansion under the Affordable Care Act (ACA) improved insurance coverage nationally, its effect on long-term melanoma survival and associated racial inequities remains insufficiently characterized. Methods: Using the National Cancer Database (2006-2023), we identified adults aged 40-64 years with a primary diagnosis of melanoma. A difference-in-differences design compared 5-year overall mortality between states that implemented Medicaid expansion by January 2014 (expansion states) and non-expansion states, which are yet to implement the policy. Models adjusted for demographic, clinical, and socioeconomic factors. Pre-specified subgroup analyses assessed heterogeneity by race and ethnicity. Results: The cohort included 288,494 patients with melanoma (mean [SD] age, 54.5 [6.8] years), of whom 171,805 (59.6%) resided in expansion states. Following ACA implementation, expansion states experienced substantially greater reductions in uninsurance and larger increases in Medicaid coverage compared with non-expansion states. Medicaid expansion was associated with a 1.1%-point absolute reduction in 5-year mortality, corresponding to approximately 1,900 fewer deaths among patients in expansion states (95% CI, ~1,030-2,405). Significant racial and ethnic heterogeneity was observed (χ² = 56.1; P < 0.001). Hispanic patients experienced the largest survival benefit (-7.0% points; 95% CI, -9.1 to -4.8), followed by non-Hispanic other racial groups (-4.1; 95% CI, -8.0 to -0.3). More modest improvements were seen among non-Hispanic White patients (-0.8; 95% CI, -1.2 to -0.3). Notably, no survival benefit was observed among non-Hispanic Black patients (-0.5; 95% CI, -6.2 to 5.2). Conclusions: Medicaid expansion was associated with meaningful improvements in long-term melanoma survival, reinforcing the central role of insurance access in a disease where outcomes hinge on early detection and timely treatment. However, the absence of benefit among Black patients underscores persistent structural barriers that are not mitigated by coverage expansion alone. These findings highlight the need for targeted, equity-focused interventions across the melanoma care continuum to ensure that advances in cancer policy and treatment translate into equitable survival gains.