Medicaid Expansion and Overall Mortality Among Individuals With Lung Cancer

Lung cancer is the leading cause of cancer-related mortality in the United States, with outcomes disproportionately worse among uninsured and socioeconomically disadvantaged populations. The Affordable Care Act (ACA), through Medicaid expansion, sought to improve access to care, yet its long-term impact on lung cancer survival remains incompletely defined. The objective of the study was to evaluate the association between Medicaid expansion and overall mortality among adults with lung cancer and to examine whether these effects differed by race/ethnicity and lung cancer histology, as well as changes in stage at diagnosis and treatment utilization.

We conducted a retrospective cohort study using the National Cancer Database including adults aged 40-64 y diagnosed with lung cancer between 2006 and 2021. States were categorized as nonexpansion, early expansion (implemented by January 1, 2014), or late expansion (implemented after January 1, 2014). The study period was divided into pre-ACA (2006-2013) and post-ACA (2014-2021). A quasiexperimental difference-in-differences approach within multivariable Cox proportional hazards models was used to estimate associations between Medicaid expansion and overall mortality, adjusting for demographic, clinical, and socioeconomic covariates. Additional analyses examined stage at diagnosis and treatment utilization.

A total of 755,328 adults aged 40-64 y with lung cancer were included, comprising 371,227 patients in the pre-ACA period and 384,101 in the post-ACA period. In adjusted difference-in-differences models, early Medicaid expansion was associated with a significant reduction in overall mortality compared with non-expansion states (hazard ratio [HR] 0.894, 95% confidence interval [CI] 0.877-0.912; P < 0.001), whereas late expansion states experienced a smaller mortality reduction (HR 0.973, 95% CI 0.947-1.000; P = 0.049). Mortality reductions were observed across racial and ethnic groups, with the largest decrease among Hispanic individuals (HR 0.754, 95% CI 0.702-0.810). Expansion was also associated with increased early-stage diagnosis (risk difference +2.28%, 95% CI 1.86-2.69) and higher surgical treatment rates (+2.01%, 95% CI 1.62-2.40), suggesting improved access to potentially curative care.

Medicaid expansion was associated with reduced overall mortality among adults with lung cancer, with greater survival gains observed in early expansion states. Expansion was also linked to earlier stage at diagnosis and increased surgical treatment, suggesting that expanded insurance coverage may improve survival by facilitating timely access to cancer care.