What’s the way forward in breast density?


Reading images of breasts with higher levels of density can present challenges for even the most experienced radiologists, and breast density is one of the strongest predictors of the failure of mammography to detect cancer.

Breast density is so much a concern that 21 US states have now enacted legislation requiring health providers to inform women if they have dense breasts, and US Congress has proposed a similar bill. 
But despite the information and advice available for women today, particularly from patient groups who are keen for women to understand the issue of density, there is little clear guidance for physicians on supporting women who ask for additional imaging exams – a challenge in the US particularly is that additional scans may not be covered by insurance. However, for women with dense breasts, additional screening is often called for, especially when taking into account other factors, such as family history, lifestyle and other health conditions. 

Additional screening? 
Dr Laszlo Tabar, Professor Emeritus of Radiology, University of Uppsala School of Medicine, Sweden, also recommends additional methods of screening. “There is currently not a single imaging method that can image all the normal or abnormal breast lesions equally well. This complex problem can be overcome by using the ‘multimodality approach’, especially when the breast tissue is ‘dense’.” 

Although as stated standard guidelines on additional screening don’t exist, many radiologists will order supplementary screens to see additional detail, such as breast MR, breast ultrasound and digital breast tomosynthesis. 

Clinical trials and the need for data
Yet, according to comments published recently in the New England Journal of Medicine, evidence to support supplemental scanning is currently lacking, although trials are underway, notably the DENSE trial in the Netherlands, looking at the efficacy of additional MRI screening for women identified as having dense breasts. Once completed, this should give radiologists clear insight into the value of supplementing mammography with additional methodologies – as well as the extent of the risk of generating an increased number of false positive reads. In addition, many studies have shown that 3D mammography has clear advantages in the screening of dense breasts – reimbursement codes for 3D mammography are now assigned in the US. 

New technologies
The uptake of digital breast tomosynthesis is growing rapidly and will support more accurate reading of a range of breast tissue, not just denser types, but until this is more widely available, mammography will remain the standard of care. 

Optimal reading conditions
For now, what can radiologists do? For Dr Petra Bun, radiologist from the BONWest Screening Centre, Leiden, Netherlands, the most useful action is to ensure you have a good contrast in the mammograms you’re reading. Plus, ensuring that the reading room is optimized: keeping the room as dark as possible and minimizing ambient light and reflection on screens is critical. All these factors support a radiologist’s ability to identify micro-calcifications in more dense breasts. Multi-modality imaging for breast studies is also a critical tool in supporting radiologists, enabling them to view multiple images in different detail to gain the best possible view of the breast. 

Until studies are complete, the one thing that is clear is that more information is needed to support radiologists in developing screening protocols for women with dense breasts. What can be done now, is to ensure the reading room is optimized to make best use of current screening technology, and be open to discussion and education around best practice.