Is Medicaid Expansion Associated with Improved Nonmetastatic Colon Cancer Survival? An Analysis of the National Cancer Database

Medicaid expansion has been associated with improved colorectal cancer screening rates and earlier stage diagnosis, but its impact on survival among colon cancer patients is unknown. We hypothesized that patients with invasive, nonmetastatic colon cancer residing in Medicaid expansion states (MES) would have better survival rates compared to patients in non-expansion states (NES). Methods This retrospective study of 86 413 patients (40-64 years old) undergoing surgical resection for a new diagnosis of invasive, nonmetastatic colon cancer included in the National Cancer Database (NCDB) from 2010 to 2015 compared overall survival (OS) in MES to NES. Cox proportional hazard models, fit for OS, and propensity score-matching (PSM) analysis were performed. Results In this sample, 51 297 cases (59.2%) lived in MES and 35 116 (40.8%) in NES. Medicaid expansion states had earlier pathological stage compared to NES (stage I 25.38% vs 24.17%, stage II 32.93 vs 33.4%, and stage III 41.69 vs 42.43%; P < .001). 5-year OS in MES was higher than NES (79.1% vs 77.3%; P < .001); however, on both multivariable analysis (MVA) and PSM analysis, MES did not have significantly different OS from NES (hazard ratio (HR), .99, 95% confidence interval (CI), .95-1.03; P = .570; HR, .99, 95% CI, .95-1.03; P = .68). Conclusion Among NCDB patients with invasive, nonmetastatic colon cancer residing in MES at time of diagnosis was associated with earlier pathological stage. However, on both MVA and PSM analysis, OS was not significantly different in MES vs NES. Research on patient outcomes, such as receipt of guideline concordant care, can further inform the impact of insurance coverage expansion efforts on cancer outcomes.