Over the last several years, an abundance of research has illustrated the diagnostic advantages of 3D mammography, or digital breast tomosynthesis (DBT), over conventional 2D mammography for breast cancer screening, particularly for women with dense breast tissue.
Unfortunately, the patients poised to benefit most from the scan are not always the ones receiving it, and disparities in access to 3D mammo may reflect larger inequities in healthcare.
Dr. Christoph Lee, director of the Northwest Screening and Cancer Outcomes Research Enterprise (NW SCORE), and professor of radiology and adjunct professor of health services at University of Washington School of Medicine, has studied 3D mammo utilization trends. We spoke to him to learn more about the problem and how to solve it.
HCB News: Earlier this year, you published research looking at access to 3D mammography across different demographics. Can you summarize your findings for us?
Dr. Christoph Lee:
We found that in 2,313,118 screening exams performed across 92 Breast Cancer Surveillance Consortium (BCSC) facilities, women of minority race/ethnicity and lower socioeconomic status experienced lower DBT access during the early DBT adoption period (5.5% of Asian American, 6.6% of Black, and 10.0% of Hispanic versus 24.0% of white women in 2013), and persistently lower DBT use even when it was available at the time of imaging five years after facility-level adoption (58.0% of Black women versus 77.2% of white women; 66.9% of those with below high school education versus 87.3% of college graduates.
Overall, we concluded that women of minority race/ethnicity, lower education, and lower income experience lower DBT screening access and/or use, especially during the early technology adoption period, suggesting potential widening in persistent breast cancer screening disparities.
HCB News: Does your research point to any explanations for the disparities you found?
While a majority of mammography facilities in the U.S. now offer DBT screening on at least one of their mammography units, less than half of all certified mammography units in the U.S. are DBT capable. That means that many women may not have access to DBT at their usual place of service. One major driving force for disparities in access to DBT screening is the fact that chronically lower-resourced settings may be the last to obtain this new technology.
HCB News: What types of patients are poised to benefit the most from 3D mammography?
We know from the Breast Cancer Surveillance Consortium that women obtaining a baseline mammogram, or first-ever mammogram, benefit the most from DBT over DM screening. We also know that women with the two middle types of breast density (scattered fibroglandular and heterogeneously dense breasts) have improved cancer detection with DBT. All women, regardless of breast density, likely benefit from DBT for decreases in false-positive recall rates.
HCB News: Can insurance play a role in leveling the playing field for access to 3D mammo?
Our analysis demonstrated that women with lower income levels continue to experience disparities in DBT screening use, even years after facility-level DBT adoption. This suggests that copays and insurance play an important role in enabling access to care. Washington state has taken the legislative step to mandate that DBT screening be offered to all women without copay. This has allowed Washington to ensure DBT access for everyone regardless of insurance status.
HCB News: Do you think public health initiatives and media campaigns could help raise awareness of 3D mammo?
We definitely want to improve health literacy around risk-based breast cancer screening. We need to do a better job of informing women about their own risk factors and what screening regimen would work best for them. It's not one-size-fits-all.
HCB News: Are these findings surprising or do they reflect a bigger picture of medical care access in the U.S.?
These findings are, unfortunately, not surprising. Traditionally underserved populations are usually the last to benefit from any new medical technology. DBT screening is no different. It's important for radiology practices and policy makers to be cognizant of these DBT screening access and use differences, and future efforts should address racial/ethnic, educational, financial, and geographic barriers to obtaining DBT screening.