37% of Black women vs. 43% of Asian-American women, 44% of Hispanic women, and 53% of white women
41% of women with less than a high school education vs. 50% of women with a college degree
44% of women living in zip codes with the lowest quartile of median household income vs. 51% of women living in zip codes with the highest quartile of median household income
"These subpopulations of women with poorer access to 3D are already traditionally underserved and more at risk for greater morbidity and mortality from breast cancer," Lee said.
The study did not address whether structural racism in healthcare environments or out-of-pocket costs might contribute to the lower access and use of new technologies among women of minority race/ethnicity. However, these may be real barriers, the researchers said.
"DBT costs more than 2D because it generates digital 'slices' of breast tissue, which take more time to acquire and to interpret," Lee said. "In 2018, Washington state enacted a law requiring facilities not to charge more for 3D screening images and interpretation. So, even if a patient's insurance doesn't cover 3D, they can still get it for the same cost as 2D screening, which is free. But most other states don't have such a law and, depending on a patient's insurance, they may be told that they will have to pay out-of-pocket for the difference."
In assessing education's potential effect, Lee said women with higher achievement might have more opportunity to explore healthcare options and to know about 3D mammography's benefits. They might seek facilities where 3D mammography is available and perhaps even ask for it directly, he suggested.
According to the FDA, more than two-thirds of U.S. screening facilities now offer DBT on at least one of their mammography units, but fewer than half of all certified units are actually DBT-capable.
Perhaps surprisingly, facility location - urban vs. rural - was not found to be a major factor of 3D mammography availability. Lee offered context.
"If there is a rural site that has one digital mammography machine, and they switch to DBT, automatically their entire patient population has DBT access - whereas large, urban facilities may have several mammography units but can only afford to replace one at a time (at a cost of about $750,000 per) to become 3D-capable. More of those patients will still be directed to the 2D technology."
He expressed concern that subpopulations of women are not receiving 3D mammography even when they have that option at their facility at the time of screening.
