Impact of Medicaid Expansion on Breast Cancer Diagnosis and Treatment in Southern States

Background: Medicaid expansion impacted patients when assessed at a national level. However, of the 32 states that expanded Medicaid, only three were Southern states. Whether results apply to Southern states that share similar geopolitical perspectives remains elusive. We aimed to assess the impact of Medicaid expansion on breast cancer diagnosis and treatment in 8 Southern states in the US.

Study design: We identified uninsured or Medicaid patients (age 40 to 64 years) diagnosed with invasive breast cancer from 2011 to 2018 in Southern states from the North American Association of Central Cancer Registries-Cancer in North America Research Dataset. Medicaid-expanded states ([MES], Louisiana, Kentucky, Arkansas) were compared with non-MES ([NMES], Tennessee, Alabama, Mississippi, Texas, Oklahoma) using multivariate logistic regression and differences-in-differences analyses during pre- and postexpansion periods; p < 0.05 was considered statistically significant.

Results: Among 21,974 patients, patients in MES had increased odds of Medicaid insurance by 43% (odds ratio 1.43, p < 0.01) and decreased odds of distant-stage disease by 7% (odds ratio 0.93, p = 0.03). After Medicaid expansion, Medicaid patients increased by 10.6% in MES (Arkansas, Kentucky), in contrast to a 1.3% decrease in NMES (differences-in-differences 11.9%, p < 0. 0001, adjusting for age, race/ethnicity, rural-urban status, and poverty status). MES (Arkansas, Kentucky) had 2.3% fewer patients diagnosed with distant-stage disease compared with a 0.5% increase in NMES (differences-in-differences 2.8%, p = 0.01, after adjustment). Patients diagnosed in MES had higher odds of receiving treatment (odds ratio 2.27, p = 0.03).

Conclusions: Unlike NMES, MES experienced increased Medicaid insured, increased treatment, and decreased distant-stage disease at diagnosis. Medicaid expansion in the South leads to earlier and more comprehensive treatment of breast cancer.