Supplemental imaging strategies facilitate early cancer detection in women with dense breasts

Supplemental breast cancer (BC) imaging techniques may help detect early cancers that standard mammograms may have missed in women with dense breasts, according to interim results from the BRAID* trial.

“[In this study,] abbreviated MRI (AB-MRI) and contrast-enhanced mammography (CEM) detected three times as many invasive cancers compared with automated whole breast ultrasound (ABUS), with cancers being half the size,” they said.

This UK trial comprised 9,361 women (median age 56 years) from 10 breast screening sites who had negative mammograms and dense breasts. They were randomized 1:1:1:1 to AB-MRI, ABUS, CEM, or standard of care (SoC; full-field digital mammography). Of these, 6,305 completed supplementary imaging and were included in the analysis.

Cancer detection rates were threefold higher with AB-MRI and CEM than ABUS (17.4 and 19.2 vs 4.2 per 1,000 examinations).

The detection rate with AB-MRI was significantly higher than ABUS (p=0.047) and non-significantly higher than CEM (p=0.62). Compared with SoC, all three supplemental imaging arms showed a significantly higher cancer detection rate, with the greatest difference observed for AB-MRI (p<0.0001).

Of the 85 cancers detected overall, 73 were invasive while 12 were pure ductal carcinoma in situ (DCIS). [Lancet 2025;405:1935-1944]

The invasive tumours detected by AB-MRI and CEM were half the size of those detected by ABUS (median, 10 and 11 vs 22 mm). The DCIS sizes in the AB-MRI and CEM arms were 10 and 27 mm, respectively. There was no DCIS in the ABUS arm.

“The small size of the additional cancers found shows that the tools are effective in early detection,” said the researchers. “All but six of the cancers were lymph-node-negative, confirming early-stage disease. While smaller cancer size should lead to improved prognosis, cancer grade is important.”

Breast density a predictor of BC risk

“BC underdiagnosis with screening mammography is a problem in women with dense breast tissue. Breast density … is a known risk factor for BC – in women with the densest breasts, there is a fourfold increased risk compared with those with fatty breasts,” said the researchers.

Moreover, dense breasts increase the likelihood of having the cancer detected at a later stage at screening, or as an interval cancer, leading to a worse prognosis. [Eur J Cancer 2018;88:48-56; Eur Radiol 2025;35:177-187] However, there is no consensus regarding the management of women with dense breasts, and the benefits of auxiliary imaging remain uncertain. [JAMA 2024;33:1918-1930]

ABUS has been a practical screening tool for dense breasts that offers broad accessibility, no radiation or contrast, and better tolerability. [Curr Breast Cancer Rep 2021;13:141-150] Evidence shows that ABUS performs comparably to handheld US, provides better reproducibility, and is tied to increased cancer detection rates and lower recall rates. [J Breast Imaging 2024;6:493-501; Eur Radiol 2010;20:734-742; Radiology 2015;274:663-673; Eur J Radiol 2016;85:1554-1563]

MRI has shown superiority to US and digital breast tomosynthesis for detecting additional cancers in women with dense breasts at average or intermediate risk for BC. [Radiology 2023;306:e221785]

CE techniques such as CEM offer alternative viable strategies, with evidence suggesting that these methods may yield higher cancer detection rates in women with dense breasts than mammography or digital breast tomosynthesis. [AJR Am J Roentgenol 2018;211:W267-W274]

“This study shows that CE techniques such as AB-MRI and CEM have a superior performance over ABUS,” said the investigators. “The [findings] will allow sophisticated modelling to estimate the cost-benefit of implementing a supplemental imaging strategy.”

“[T]his study has global implications for all countries where screening is undertaken for women with dense breast tissue,” noted lead author Professor Fiona Gilbert from the University of Cambridge in the UK, in a press release.