If you're a low-income woman, you're more likely to get screened for breast cancer if you live in a state that expanded Medicaid under the Affordable Care Act than in a state that didn't.

According to new research, low-income women who lived in a handful of early-adopter states that implemented Medicaid expansion by 2011 were 25 percent more likely to be screened for breast cancer in 2012 than women in non-expansion states. That's a big change from 2008, when low-income women in both sets of states had similar odds of being screened. The study was presented last week at the annual meeting of the Radiological Society of North America.

The researchers weren't surprised by the results and had hoped to see an effect from the Medicaid expansion, says lead author Soudabeh Fazeli Dehkordy. "We would expect to see actually greater differences if we redo the analysis today with 2015" data, said Fazeli Dehkordy, a first-year resident at St. John Providence Hospital in Southfield, Mich.

Under the Affordable Care Act, states had the option of expanding Medicaid to cover low-income people living at or below 138 percent of the federal poverty level. Thirty states (including Pennsylvania and New Jersey) and the District of Columbia have expanded the health-insurance program.

Fazeli Dehkordy and her colleagues used data from the 2008 and 2012 Behavioral Risk Factor Surveillance System to look at roughly 31,000 American women ages 40 to 70 who self-reported how often they got mammograms. When the researchers adjusted for age, race, education, and income, they found that low-income women in the early-expansion states in 2012 - which included California, Connecticut, Minnesota, New Jersey, Washington, and the District of Columbia - were 25 percent more likely to get screened than women in non-expansion states.

Several studies have indicated a general decline in mammography rates after updated recommendations from the U.S. Preventive Services Task Force in 2009, Fazeli Dehkordy says. Those recommendations suggested women could wait until age 50 before beginning regular mammograms and, at that point, begin getting them every other year. "There has been a lot of controversy regarding the importance of screening mammography, especially regarding the best age," Fazeli Dehkordy says.

Indeed, the guidelines can still be confusing to women: The American Cancer Society updated its guidelines in October, pushing back the age at which it recommends women begin annual screenings, from 40 to 45.

Yet despite the overall decline in screening rates, the rates among low-income women stayed steady from 2008 to 2012 in states that expanded Medicaid early on, the researchers found.

The next step for research, Fazeli Dehkordy says, is to explore whether expanded coverage and more mammograms translate to better health outcomes with regard to breast cancer. For the most recent study, the researchers did not look at whether low-income women now on Medicaid had difficulty finding providers where they could obtain screenings or specialists to follow up with if a screening finds something abnormal.

Kaiser Health News is a national health policy news service that is part of the nonpartisan Henry J. Kaiser Family Foundation