M.D. Alert

Published: March 5, 2021

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(Reuters Health) – Women have better screening outcomes with digital breast tomosynthesis, but a new study suggests that Black women have less access to this imaging modality.

Researchers examined data on 385,503 women screened at one of 63 U.S. breast imaging facilities between 2015 and 2019. Overall, these women underwent a total of 542,945 screenings that combined digital breast tomosynthesis with digital mammography, as well as 261,359 screenings done with digital mammography alone.

Compared to digital mammography alone, screening that also included breast tomosynthesis was associated with lower odds of recall (odds ratio 0.87), the researchers report in the Journal of the American College of Radiology.

With breast tomosynthesis, recall rates were lower compared to digital mammography alone (8.74% vs 10.06%), cancer detection rates were higher (4.73% vs 4.60%), and positive predictive values from the first screening were better (5.29 vs 4.450).

Even though these benefits were seen among women of all races, the study also found that a smaller proportion of screenings for Black women were done using breast tomosynthesis (44%) than for Caucasian women (61%), Asian women (63%), or women from other racial and ethnic groups (48%).

“Digital breast tomosynthesis (DBT) screening provides a more accurate assessment of the breasts by both increasing invasive cancer detection while also decreasing false positive recalls,” said senior study author Dr. Emily Conant, division chief of breast imaging for Penn Medicine and a professor of radiology at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.

“This combination is a double win – fewer cancers missed with DBT screening coupled with less unnecessary imaging which may cause both anxiety and additional cost,” Dr. Conant said by email.

Several factors likely contribute to the disparities in access to DBT experienced by Black women in the study, Dr. Conant said. It may partially be explained by a lack of health insurance, or high out-of-pocket fees for DBT, as well as by limited access to screening facilities that use this modality and by some distrust of the healthcare system.

“Furthermore, research has shown that psychosocial factors may influence women’s decisions to screen, including distrust of the health care system, fear, fatalistic perceptions of cancer, inaccurate perceptions of risk, and associations with stigma,” Dr. Conant added. “This is augmented by other screening barriers that Black women may face, including transportation access, child and elder care, and challenges securing time off work.”

One limitation of the study is that the screening centers included in the analysis may not be representative of all centers in the U.S. or practice in other countries, the study team notes. Other limitations include the underrepresentation of Asian and Hispanic women, as well as a lack of data on income, insurance, and socioeconomic status.

These individual patient characteristics likely contribute to screening decisions and outcomes, but it’s also likely that provider recommendations and implicit bias among clinicians play a role, said David Chang, an associate professor of surgery at Harvard Medical School and director of Healthcare Research and Policy Development at the Codman Center at Massachusetts General Hospital in Boston.

“The take-home message for clinicians might be, ‘be aware of your blind spots when it comes to treating non-white patients’,” Chang, who wasn’t involved in the study, said by email.

Providers are likely to make assumptions about a patient’s preferences for screening based on the characteristics they think they can observe about the patient, said Dr. Katherine Reeder-Hayes, chief of breast medical oncology at the University of North Carolina-Lineberger Comprehensive Cancer Center in Chapel Hill.

“For instance, they may assume that a patient who appears to be a member of a racial minority group, or who does not speak English, would not want to incur additional cost for DBT, would not understand the choice they were being offered, or would not want to travel further to a facility offering DBT,” Dr. Reeder-Hayes, who wasn’t involved in the study, said by email.

“Those types of assumptions end up compounding the segregation of patients into different types of facilities that are already occurring due to other social determinants of access to healthcare,” Dr. Reeder-Hayes said.