Black Women Show Higher Background Parenchymal Enhancement on Breast MRI: Study Finds
USA: Black women undergoing contrast-enhanced breast MRI are more likely to show higher levels of background parenchymal enhancement (BPE) than White women, despite generally having lower breast density, a new study published in Radiology has found. The findings highlight potential gaps in current breast cancer risk assessment strategies that rely heavily on mammographic breast density.
The study was led by Mattia A. Mahmoud, MPhil, from the Department of Biostatistics, Epidemiology, and Informatics at the Perelman School of Medicine, University of Pennsylvania. Breast density, assessed using BI-RADS, is central to breast cancer risk assessment and decisions on supplemental MRI, but current models may underestimate risk in Black women.
Background parenchymal enhancement is an MRI marker of hormonally active breast tissue and has been independently associated with increased breast cancer risk. However, BPE has been understudied in Black women, despite their higher breast cancer–specific mortality.
To address this gap, the researchers performed a retrospective cross-sectional analysis of women without prior breast cancer who underwent mammography followed by breast MRI between 2016 and 2023. The study included 388 Black women and 2,101 White women, with mean ages of 47 and 48 years, respectively, across four sites within the University of Pennsylvania Health System. BPE was assessed qualitatively using BI-RADS categories and classified as low or high, alongside evaluation of mammographic breast density.
The following were the findings:
- Fewer Black women had extremely dense breasts on mammography compared with White women (11% vs 21%).
- The difference in the prevalence of extremely dense breasts between the two groups was statistically significant.
- The proportion of women with high background parenchymal enhancement on breast MRI was similar between Black and White women.
- High BPE was observed in 38% of Black women and 33% of White women.
- The unadjusted difference in high BPE prevalence between the two groups was not statistically significant.
- After adjusting for breast density, Black women were more likely to have high BPE levels than White women.
- Black women had approximately 31% higher odds of high BPE compared with White women after density differences were eliminated.
- This association remained statistically significant after adjustment.
According to the authors, these findings suggest that breast density does not fully capture variations in hormonally active breast tissue. “BPE may represent an independent imaging biomarker that reflects breast cancer risk not identified through mammography alone,” the researchers noted. They also highlighted that BPE assessment is subject to interreader variability, as it is currently evaluated qualitatively.
The study population represents a select group, as only a small proportion of women undergoing breast imaging in the United States receive breast MRI. As a result, the findings should be interpreted in the context of women who already meet clinical criteria for MRI evaluation.
Despite these limitations, the results underscore the importance of further research into MRI-based imaging markers. The authors concluded that incorporating BPE into breast cancer risk assessment models may improve risk stratification and help address disparities in screening and prevention, particularly among Black women.
Reference:
Mahmoud MA, Chen J, Edmonds CE, Fayanju OM, Zeballos Torrez CR, McCarthy AM. Black-White Racial Differences in Background Parenchymal Enhancement at Breast MRI. Radiology. 2026 Jan;318(1):e251041. doi: 10.1148/radiol.251041. PMID: 41528221.
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