Additional contrast-based imaging may lead to earlier cancer detection in women with dense breasts

By Rebecca Jenkins

Cancer is more likely to be detected in women with dense breasts when they are offered additional imaging using contrast-based techniques rather than ultrasound, a world-first randomised trial finds.

Mammography screening in women with dense breast tissue had low sensitivity, meaning there was a higher chance of their cancer being picked up at a later stage at screening, or as an interval cancer, resulting in a worse prognosis, UK researchers wrote in The Lancet.

Supplemental imaging using MRI or ultrasound was known to aid early cancer detection, but there were no prospective trials directly comparing abbreviated MRI, contrast-enhanced mammography and whole breast ultrasound as supplemental imaging tools in women with dense breasts.

For the Breast screening-Risk Adapted Imaging for Density (BRAID) study, researchers enrolled 9361 participants, median age 56 years, who had normal mammograms and dense breast tissue.

The women were batch-allocated across 10 UK breast screening sites to abbreviated breast MRI, automated whole breast ultrasound (ABUS), contrast-enhanced mammography or standard of care (full-field digital mammography).

The researchers found abbreviated MRI and contrast-enhanced mammography detected an additional 17 cancers per 1000 examinations compared with four cancers per 1000 examinations with ABUS.

The median invasive tumour size of 10 mm was similar on the contrast-enhanced techniques and was half that of those found by ABUS. However, the contrast imaging tests had higher recall rates: 9.7% for abbreviated MRI and for contrast-enhanced mammography, compared with 4% for ABUS.

‘This study shows that supplemental imaging could lead to earlier detection of cancer in women with dense breasts but does not estimate the level of overdiagnosis,’ the researchers concluded.

Commenting on the research, Dr Brooke Nickel, NHMRC Emerging Leader Research Fellow at the School of Public Health, The University of Sydney, called the BRAID trial a landmark study that provided new knowledge on initial outcomes comparing three different types of supplemental imaging tests for women with dense breasts.

However, Dr Nickel, who is also part of the Wiser Healthcare collaboration, which focuses on research into overdiagnosis and overtreatment, cautioned that the study had not examined longer-term outcomes such as reduction in breast cancer-specific mortality or longer-term harms, including overdiagnosis.

‘Comparison of three different modalities is of important value for screening services considering supplemental imaging, particularly filling an evidence gap in terms of contrast-enhanced mammography in population-based screening,’ she said.

There was continuing debate about how to manage women with dense breasts, Dr Nickel said, particularly through population-based screening programs.

‘At this time, international consensus on supplemental imaging in women with dense breasts is lacking, with the quality of current guidelines being quite variable and recommendations largely based on low-quality evidence,’ she said.

‘However, studies such as BRAID will inevitably impact and change this moving forward.’

Dr Nickel said breast density notification was now recommended by the national screening program, BreastScreen Australia.

‘However, they acknowledge that there is currently no  consensus on the optimal supplemental imaging test(s) for women with dense breasts and recommend that women speak to their GPs about their breast density and other risk factors,’ she said.

‘Before Australia and other jurisdictions can move to a more personalised approach, there needs to be evidence-informed clinical pathways for women with dense breasts within the specific screening program in terms of both effectiveness outcomes and the screening program’s feasibility and acceptability to women.’

The study follows the recent conclusion of the BreastScreen Australia National Policy and Funding Review which was aimed at enhancing the screening program. Outcomes of the review, which considered latest evidence in breast cancer screening including breast density as a breast cancer risk factor and its impact on the effectiveness of screening modalities, are expected to be released later this year, the Federal Department of Health, Disability and Ageing confirmed in a statement.

Lancet 2025; https://doi.org/10.1016/S0140-6736
(25)00582-3.