Women diagnosed with breast cancer were significantly less likely to die from the disease if they lived in states that expanded Medicaid eligibility, according to a large new study published in JAMA Network Open. However, the benefits of expansion were not shared equally across all racial, ethnic, and income groups.
The study analyzed data from approximately 1.6 million women aged 40 to 64 who were diagnosed with breast cancer between 2006 and 2021. Researchers from Howard University, the University of Alabama, Henry Ford Hospital in Michigan, and other institutions examined differences in survival outcomes between states that expanded Medicaid under the Affordable Care Act and those that did not.
About 58% of the women in the study lived in Medicaid expansion states, while roughly 42% lived in nonexpansion states. Most states began expanding Medicaid eligibility in 2014 following the implementation of the Affordable Care Act, often referred to as Obamacare.
Overall, the researchers found that Medicaid expansion was associated with lower mortality rates across all stages of breast cancer, regardless of race, ethnicity, or neighborhood income. The largest absolute decline in deaths was observed among women with advanced-stage cancer, particularly those whose disease had spread to other organs.
When broken down by race and ethnicity, Hispanic women experienced the greatest relative benefit. They were 19% less likely to die from breast cancer if they lived in a Medicaid expansion state. Smaller improvements were seen among non-Hispanic Black women and women living in lower-income neighborhoods, while white women experienced the smallest difference in mortality rates.
Dr. Oluwasegun Akinyemi, director of Howard University College of Medicine’s Clive O. Callender Outcomes Research Center and a coauthor of the study, said the substantial gains among Hispanic women may be linked to historically high rates of uninsurance prior to Medicaid expansion.
Despite overall improvements, Black women benefitted less from expansion compared with other groups. Black women continue to face higher breast cancer mortality rates than white women, even though they are diagnosed less frequently, in part because they are more likely to be diagnosed at later stages of the disease.
Akinyemi noted that the limited benefit among Black women is partly due to geography. Many Black patients live in Southern states, where the majority of states have declined to expand Medicaid. States that have not expanded Medicaid include Alabama, Florida, Georgia, Mississippi, South Carolina, Tennessee, and Texas, along with Kansas, Wisconsin, and Wyoming.
The study also examined differences based on neighborhood income. Women living in higher-income areas and those who received immunotherapy treatments had lower mortality rates overall, suggesting that insurance coverage improves access to advanced and potentially life-saving treatments.
The findings come amid significant changes to Medicaid policy. In July, President Donald Trump signed a sweeping tax and spending bill that is expected to cut federal Medicaid funding by more than $900 billion over the next decade. According to estimates from the Center on Budget and Policy Priorities, those reductions could result in approximately 15 million people losing Medicaid coverage nationwide.
The study underscores how insurance access can shape cancer outcomes — and how policy decisions may widen or narrow existing health disparities.
