November 2019

Thursday, November 28, 2019 - The outcomes of the multicentre DENSE trial on breast cancer, which was conducted in The Netherlands and first presented at the European Congress of Radiology (ECR) 2019, has now been published in The New England Journal of Medicine. Presented by Prof. Carla H. van Gils at an ECR Clinical Trials in Radiology (CTiR) session, the results provide practical insights into the use of supplemental magnetic resonance imaging (MRI) in screening for breast cancer, and further strengthen the ECR’s reputation as the No.1 meeting point for groundbreaking imaging innovation and cutting-edge radiology research from across the globe.  

 ‘This is an exciting trial led by Professor Carla van Gils and we were happy to have her present it as a landmark clinical trial during a CTiR session at ECR 2019’, said Professor Marc Dewey, Chairperson of the ECR Programme Planning Committee’s Scientific Paper Subcommittee. ‘I would like to wholeheartedly congratulate Carla and her team for having accomplished this impressive analysis of interval cancer in a large multicenter randomized trial answering pivotal questions about the clinical effectiveness of supplemental MRI screening for women with extremely dense breast tissue.’

Titled, ‘Supplemental MRI Screening for Women with Extremely Dense Breast Tissue’, the publication describes the first results of the DENSE trial which involved 40,373 women between the ages of 50 and 75 years with extremely dense breast tissue and normal results from a mammography screening. These women were divided into two groups, those who were invited for supplemental MRI screening (8061 women), and those who received only a mammography screening (control group 32,312 women). 

The primary outcome of the DENSE trial, according to its protocol, is the number of interval cancers in the MRI group compared to the control group after three screening rounds, i.e. six years. Today’s publication of the DENSE trial in the NEJM represents the first interim analysis of this primary outcome after the first screening round. The study investigators showed that supplemental MRI screening reduced the interval-cancer rate from 5.0 per 1000 screenings in the control group to 2.5 per 1000 screenings in the MRI-invitation group. This reduced the interval-cancer rate in the supplemental MRI group by 1.3 per 1000 person-years. Importantly, the false positive rate of MRI was 8.0% (79.8 per 1000 screenings) and only 26.3% of patients who had a breast biopsy following MRI actually had breast cancer. Overall mortality is not a pre-specified outcome of the trial and was similar in the two groups after two years of follow-up (65 of 8061 patients in the supplemental MRI group and 236 of 32,312 patients in the mammography control group).

Informed consent for participation was only requested from women assigned to the MRI group in order to avoid anxiety and limit cross-over to MRI in the control group. Data on the primary outcome of interval cancer in the two groups was retrieved from the Netherlands Cancer Registry. Only 4783 of the 8061 patients (59.3%) invited to supplemental MRI screening actually underwent MRI, mostly due to MRI-related inconveniences and anxiety regarding the result according to an earlier report of the group in 2018.* Moreover, women with higher socio-economic status participated in the MRI screening more often than women with lower status. According to the intention-to-treat design however, all patients invited for MRI screening were included in the intervention group. In comparison with the control group, MRI screening halved the rate of interval breast cancer. When only the MRI participants were considered, the interval-cancer rate was further reduced to 0.8 per 1000 screenings further supporting the need to reduce MRI-related inconveniences, for instance, by abbreviated protocols.**

In the accompanying editorial, Deputy Editor of the journal, Dan. L. Longo, highlights the importance of the paper, and calls for research to be extended to determine if the use of MRI screening for women with dense beast tissue can improve survival rates. ‘The findings of Bakker et al. are important, since they provide high-quality data from a randomized trial where none existed.’ He goes on to conclude that, ‘the findings of this trial are likely to reinforce the idea that MRI screening is important in women with dense breast tissue. But will we be putting these women at increased risk of procedures without contributing to their eventual survival?’ 

Professor Dewey concluded that, ‘It will be of great interest to see the results of the DENSE trial following the second and third screening round to further inform the radiology community about the risks and benefits of supplemental MRI screening in women with extremely dense breast tissue.’

Clinical Trials in Radiology sessions will return at ECR 2020 and will take place in Room Y from March 11-13 every day at 2 PM until 3:30 PM. The CTiR sessions will cover results from the second screening round of the DENSE trial and 17 further trials about imaging of prostate cancer, pancreatic cancer, breast cancer, Hodgkin lymphoma, as well as the topics of artificial intelligence, radiation safety, pulmonary embolism, stroke and interventional radiology.

You can register for the congress now for a special reduced fee, available for all those who register before December 12.


van Gils

Professor Carla H. van Gils, who presented at the ECR 2019 CTiR session
© UMC Utrecht


The DENSE trial is published in the NEJM and can be accessed here.

The full citation of the report is: Bakker MF, de Lange SV, Pijnappel RM et al. Supplemental MRI Screening for Women with Extremely Dense Breast Tissue’. N Engl J Med 2019;381:2091-102. DOI: 10.1056/NEJMoa1903986

The publication is accompanied by a Quick Take summarizing the study in a short video.