Medicaid Expansion and Overall Mortality Among Individuals With Renal Cell Carcinoma.

INTRODUCTION: Renal cell carcinoma (RCC) remains a major cause of cancer-related morbidity, mortality, and economic burden in the United States. Medicaid expansion under the Affordable Care Act increased access to insurance coverage for low-income adults, yet evidence regarding its impact on RCC survival remains limited. We evaluated the association between Medicaid expansion and overall and 5-year survival among adults aged 40-64 years diagnosed with RCC. METHODS: We conducted a retrospective cohort study using National Cancer Database data (2006-2021). States were classified as Medicaid expansion or nonexpansion using National Cancer Database policy variables. The pre-expansion period was defined as 2006-2013 and the postexpansion period as 2014-2021. Difference-in-differences Cox proportional hazards models estimated the association between Medicaid expansion and mortality, adjusting for demographic, clinical, tumor, facility, and socioeconomic characteristics. Royston-Parmar flexible parametric models estimated absolute differences in 5-y survival. RESULTS: A total of 284,967 adults with RCC were identified. Medicaid coverage increased from 7.9% to 16.7% in expansion states and from 6.9% to 9.3% in nonexpansion states (P < 0.001). The uninsured rate declined from 7.3% to 1.9% in expansion states, versus 8.2%-4.7% in nonexpansion states (P < 0.001). Medicaid expansion was associated with a 7.5% reduction in overall mortality (hazard ratio, 0.93; 95% confidence interval [CI], 0.91-0.94; P < 0.001). Five-year mortality decreased by 1.4 percentage points overall (95% CI, -1.6 to -1.3; P < 0.001), with the largest benefit among Hispanic patients (-6.3 percentage points; 95% CI, -7.5 to -5.0; P < 0.001). No significant 5-y survival changes were observed among non-Hispanic Black patients (-0.3 percentage points; P = 0.57). CONCLUSIONS: Medicaid expansion was associated with substantial improvements in insurance coverage and clinically meaningful reductions in RCC mortality, particularly among Hispanic and non-Hispanic White patients. Persistent survival gaps among non-Hispanic Black patients highlight the need for interventions beyond insurance coverage alone to achieve equity in RCC outcomes.