The Patient Protection and Affordable Care Act, also known as Obamacare, has been the subject of intense debate since it was enacted in 2010. But the law has been around long enough that medical experts can assess its impacts. A new study has found the law has significantly helped women battling breast cancer, but only in those states that expanded Medicaid insurance coverage under the law.

Yale University researchers, using information from nearly 2 million women in the National Cancer Database, found in the states that expanded Medicaid, the percentage of women who had breast cancer but no health insurance was cut nearly in half. In states that did not expand coverage, the percentage was unchanged.

The team found the percentage of women battling breast cancer in its late stages also fell dramatically, and the numbers were particularly strong among younger women. In comparison, women with private insurance or Medicare were half as likely to present to a physician with late-stage breast cancer. The authors noted that despite improved access to insurance, those with Medicaid or who are uninsured still have a higher incidence of advanced disease compared with those with private insurance.

Experts say the study shows that when you expand coverage, you see more cases, but you catch them at an earlier stage when the chances for successful outcomes are greater because of access to health care.

At a time when an unprecedented public health emergency, COVID-19, has focused attention on our public health infrastructure, this study adds a new element to the national discussion on how best to improve access to health care for all of our citizens.