Abstract
IMPORTANCE: Pancreatic cancer is among the deadliest malignancies, with 5-year survival estimated at 13%. Medicaid expansion offers the opportunity to assess whether broader insurance eligibility improves outcomes. OBJECTIVE: To evaluate whether state-level Medicaid expansion was associated with reduced mortality and increased surgical resection among adults with pancreatic cancer and whether effects varied across demographic and socioeconomic subgroups. DESIGN, SETTING, AND PARTICIPANTS: This was an observational cohort study using generalized difference-in-differences Cox and logistic regression models. Data were drawn from the Surveillance, Epidemiology, and End Results (SEER) Research Plus database (2006-2019). Included were patients from a population-based registry including 12 US states with variable Medicaid expansion timelines. Patients were aged 20 to 64 years with pancreatic cancer, excluding those 65 years or older. Patients were categorized by state Medicaid expansion status as follows: nonexpansion, early (expansion in 2011), on time (expansion in 2014), and late (expansion in 2017). Groups were propensity score matched for demographic and clinical covariates. Data were analyzed between May and July 2025. EXPOSURE: Residence in a state with Medicaid expansion, classified by timing. Residents of nonexpansion states served as controls in all analyses. MAIN OUTCOMES AND MEASURES: The primary outcome was 2-year all-cause mortality. The secondary outcome was rate of surgical resection. RESULTS: A total of 51 707 patients were included in this analysis; patients were categorized by state Medicaid expansion status as follows: 8758 nonexpansion, 32 818 early, 6605 on time, and 3522 late. Among 51 703 patients (age range, 20-64 years; 29 212 male [56.5%]) diagnosed with malignant-coded pancreatic cancer, Medicaid expansion was associated with reduced 2-year mortality in early (hazard ratio [HR], 0.91; 95% CI, 0.86-0.96), on-time (HR, 0.91; 95% CI, 0.84-0.98), and late (HR, 0.94; 95% CI, 0.89-0.99) expansion states. Decreased associated mortality generally emerged after 3 years' postimplementation. Expansion narrowed geographic disparity in survival for patients in midsized (HR, 0.94; 95% CI, 0.88-1.00; P = .04) and small (HR, 0.88; 95% CI, 0.79-0.98; P = .02) metropolitan counties but did not improve income-related disparity. Patients with stage II to III disease had an associated decrease in mortality compared with stage IV (stage II: HR, 0.91; 95% CI, 0.86-0.97; P = .002; stage III: HR, 0.81; 95% CI, 0.76-0.87; P < .001). Expansion was also associated with a 19% relative increase in the odds of surgical resection (odds ratio, 1.19; 95% CI, 1.10-1.30). CONCLUSIONS AND RELEVANCE: Results of this cohort study reveal that Medicaid expansion was associated with improved survival and surgical access for patients with pancreatic cancer, although improvements were delayed and uneven. Persistent income-related disparities highlight the need for additional policies to achieve equitable outcomes.