MRI Biomarker Enhances Breast Cancer Risk Assessment

MRI Biomarker Enhances Breast Cancer Risk Assessment

Recent research emphasizes the potential significance of background parenchymal enhancement (BPE) as an MRI biomarker that could refine breast cancer risk assessment. Traditionally, breast density has been a key metric in evaluating breast cancer risk and the necessity for supplemental MRI screening. However, a new study suggests that BPE might provide crucial risk information, particularly for Black women, that breast density alone does not capture.

Anne Marie McCarthy, ScM, PhD, an associate professor at the University of Pennsylvania Perelman School of Medicine, highlights a concerning disparity: “Black women in the U.S. have 40% higher breast cancer mortality compared to white women.” This research, which McCarthy coauthored, reveals that Black women are more prone to high BPE on MRI scans than their white counterparts, even though they generally have less dense breast tissue.

Current screening approaches prioritize mammographic breast density, which is associated with increased cancer risk and reduced detection sensitivity. However, McCarthy explains that while breast density indicates the amount of fibroglandular tissue relative to fat, BPE measures the enhancement of normal breast tissue on contrast-enhanced MRI, potentially reflecting hormonally active tissue. Importantly, studies suggest that increased BPE is linked to higher breast cancer risk independent of density.

The study, involving 2,489 women without a breast cancer history, included 388 Black and 2,101 white participants. Findings revealed that Black women were less likely to have extremely dense breasts (11% versus 21%) but had a 31% higher likelihood of exhibiting high BPE after adjusting for relevant factors such as age, menopausal status, and body mass index. This suggests that BPE might highlight hormonal or metabolic factors not represented by breast density alone.

Radiologists utilize BI-RADS terminology to categorize BPE levels as minimal, mild, moderate, or marked. These distinct classifications underscore the biomarker’s potential as an additional risk indicator. Michael H. Fuchsjäger, MD, and Gabriel Adelsmayr, MD, PhD, from the Medical University of Graz, in a related editorial, cautioned against relying solely on density-centered risk assessments, arguing that BPE could offer a more comprehensive understanding of risk in a hormone-driven environment.

Both McCarthy and Fuchsjäger stress the need for balance between harnessing BPE’s promise and addressing accessibility barriers to breast MRI. They warn that populations that could benefit most from BPE’s insights, particularly Black women, may not have adequate access to MRI screening. Therefore, it’s crucial to expand MRI access to ensure equitable cancer risk assessment.

Before BPE can be recognized in clinical guidelines, further validation through larger, diverse studies is essential. McCarthy suggests that BPE might refine individualized risk assessment for women overlooked by current models based on family history or density alone.

In conclusion, while BPE offers promising avenues for enhanced risk assessment, radiologists are advised to report BPE consistently and cautiously, as guidelines and evidence aplenty for informed clinical decision-making are still developing. With these nuances in understanding breast cancer risk biomarkers, efforts toward achieving equity in breast cancer care can be significantly bolstered.