Kentucky expanded Medicaid coverage in 2014, taking its cue from the Affordable Care Act and including individuals and families with incomes up to 33 percent above the federal poverty line. The state’s uninsured rate dropped from 19 percent to 7 percent as a result. According to a new study published in the Journal of the American College of Surgeons, the move also improved the quality of breast cancer care, leading to earlier diagnosis and an increased rate in breast-conserving therapy.

“What we learned is that the expansion of some form of third-party coverage for health care leads to people doing more things that are intrinsically good for their health,” said lead author Hiram C. Polk Jr., MD, of the Hiram C. Polk Jr. Department of Surgery at the University of Louisville, in a prepared statement.

Polk also explained why his team viewed breast cancer as a helpful way to measure the impact expanding Medicaid had on the quality of healthcare in Kentucky. “Breast cancer and colon cancer are very common cancers,” he said in the same statement. “Our goal was to get an early measure of what really happened with Medicaid expansion.”

The authors examined data from the Kentucky Cancer Registry for women ages 20-64 who were diagnosed with breast cancer between 2011 and 2016. The years before expansion, 2001-2013, were then compared with the years after expansion, 2014-2016.

More than 3 percent of breast cancer patients in the state were uninsured before expansion and more than 10 percent were on Medicaid. After expansion, just 1 percent of patients were uninsured and more than 15 percent were on Medicaid.

In addition, diagnosis of early stage breast cancer increased from 64.5 percent of cancers to more than 66 percent after expansion. And breast-conserving operations, which help patients avoid procedures such as mastectomies, increased from 44 percent to more than 48 percent after expansion.

What, exactly, do these statistics tell us about how healthcare in the state has changed?

“In the absence of information about screening and diagnostic mammography, an earlier stage at diagnosis might represent a surrogate for more women taking advantage of recommended breast cancer screening,” Polk and colleagues wrote. “Similarly, the increase in breast-conserving therapy might reflect both treatment of earlier-stage disease and improved patient access to and willingness to undergo radiation therapy, with the idea of improved access supported by a decrease in time from operation to radiation in the current study. All of these observations point to an improvement in diagnosis and appropriateness of treatment—two key elements of quality breast cancer care—in women with breast cancer associated with Medicaid expansion in Kentucky.”