LAUSR

BACKGROUND Insurance status has been associated with disparities in stage at cancer diagnosis. We examined how Medicaid expansion (ME) impacted diagnoses, surgical treatment, use of neoadjuvant therapies (NCRT), and outcomes for Stage II and III rectal cancer. STUDY DESIGN We used 2010-2017 American College of Surgeons National Cancer Database (NCDB) to identify patients ages 18-65, with Medicaid as primary form of payment, and were diagnosed with Stage II or III rectal cancer. Patients were stratified based on Census bureau division's ME adoption rates of High, Medium, Low. Overall trends were examined, and patient characteristics and outcomes were compared before and after ME date of 1/1/2014. RESULTS Over 8 years of NCDB data examined, there was an increasing trend of Stage II and III rectal cancer diagnoses, surgical resection, and use of NCRT for Medicaid patients. We observed an increase in age, proportion of White Medicaid patients in Low ME divisions, and proportion of fourth income quartile patients in High ME divisions. Univariate analysis showed decreased use of open surgery for all 3 categories after ME, but adjusted odds ratios (aOR) were not significant based on multivariate analysis. NCRT utilization increased after ME for all 3 ME adoption categories and aOR significantly increased for Low and High ME divisions. ME significantly decreased 90-day mortality. CONCLUSIONS Medicaid expansion had important impacts on increasing Stage II and III rectal cancer diagnoses, use of NCRT, and decreased 90-day mortality for patients with Medicaid. Our study supports increasing health insurance coverage to improve Medicaid patient outcomes in rectal cancer care.