DENSE Trial Second Round Results
Results from the second round of the DENSE trial were published in the May 2021 issue of Radiology.1 The DENSE trial is a multicenter, randomized controlled trial in the Netherlands and has enrolled 40,373 women between the ages of 50 and 75 years with extremely dense breast tissue and previous normal results on a mammogram. The question being asked in the DENSE trial is whether the addition of MRI to standard breast cancer screening with mammography can improve early detection and reduce interval breast cancers in women with extremely dense breasts.2
The problem for women with dense breasts is two-fold. Dense breast tissue increases breast cancer risk and decreases the probability of cancer being detected on a mammogram.3 Supplemental imaging, with MRI for example, is known to increase the cancer detection rate in women with dense breasts, but whether this improves health outcomes remains an open question.4
In the first round of the DENSE trial, the prevalence screening round, the MRI cancer-detection rate for women with a previous negative mammogram was 16.5 per 1000 screenings.2 The interval cancer rate was 2.5 per 1000 screenings in women invited for supplemental screening with MRI (n = 8061) and 5.0 per 1000 screenings in the mammography only group (n = 32,312). The interval cancer rate was 0.8 per 1000 screenings in women who actually underwent MRI. However, this increased cancer detection rate and decrease in interval cancers with MRI came at the cost of an increased false-positive rate.
These screening performance indicators were investigated again in the second round (incidence round) of the DENSE trial after a two-year screening interval.1 There were 3426 women who underwent a second MRI screening. The cancer detection rate was 5.8 per 1000 screenings in this incidence round, which was lower than the first round as expected because of a reduction in the number of prevalent cancers from the first round of screening. There was a drop in the false-positive rate from 79.8 per 1000 screening examinations in the first round to 26.3 per 1000 screening examinations in the second round. This sharp reduction in false-positive rate in the second round can be explained by the availability of prior MRI examinations as well as the increased experience of the radiologists over the course of two rounds of reading MRI screening examinations of women at average risk of breast cancer with extremely dense breast tissue.
In the video below, Dr. Carla van Gils, principal investigator of the DENSE trial, presents results from the second round and provides additional details.
References
1. Veenhuizen et al. Radiol 2021; 299:278-286
2. Bakker et al. N Engl J Med 2019; 381:2091-2102
3. Wanders et al. Breast Cancer Res Treat 2017; 162:95-103
4. Melnikow et al. Ann Intern Med 2016; 164:268-278
