“Cancer stage is the strongest predictor of survival for patients. Long-standing disparities in mortality from screening-amenable cancers between high-income and low-income adults have been driven in large part by differences in metastatic cancer rates,” said study author Uriel Kim, PhD, in a press release. “Medicaid expansion under the Affordable Care Act was associated with a significant reduction in the likelihood of being diagnosed with deadly metastatic cancer among Americans with low income. These improvements represent substantial progress in closing a persistent gap in cancer survival between Americans with high and low income.” Dr. Kim is a medical student and researcher at Case Western Reserve University School of Medicine’s Center for Community Health Integration in Cleveland, Ohio.
The study used state cancer registry data linked with block group-level income data to identify patients aged between 30 and 64 years diagnosed with incident invasive breast (female), cervical, colorectal, or lung cancer between 2011 and 2016. Patients who were either uninsured or had Medicaid insurance at the time of their diagnosis were included. The association between exposure (pre-expansion [2011-2013] vs. postexpansion [2014-2016]) and the outcome (metastatic vs. nonmetastatic disease) at diagnosis was evaluated.
Final analysis included 12,760 patients. When adjusting for possible confounders, patients diagnosed postexpansion were 15% less likely than those diagnosed pre-expansion to have metastatic disease (adjusted odds ratio [aOR]=0.85; 95% confidence interval [CI], 0.77 to 0.93). in a separate analysis of patients with private insurance living in high-income communities, the difference between postexpansion compared to pre-expansion outcomes were not significant (aOR=1.02; 95% CI, 0.96 to 1.09).
The study, which was published in Cancer, also points to improved access to preventative care in low-income communities, according to senior study author Johnie Rose, MD, PhD. “This fact is particularly relevant in the era of the COVID-19 pandemic as tens of millions of people have lost their jobs, and record numbers are expected to rely on safety net programs like Medicaid,” said Dr. Rose, who is an assistant professor at Case Western Reserve University School of Medicine’s Center for Community Health Integration.
The researchers summarized, “Medicaid expansion is associated with a narrowing of a critical cancer outcome disparity in adults from low‐income communities.”