Women with dense breasts have an increased risk of breast cancer, while dense breast tissue also decreases the sensitivity of mammography for detecting breast cancer. In Canada, different provinces have recently started notifying women of their breast density in a mammogram results letter, with BC becoming the first province to begin notifying women in October 2018.4 Many of these provincial screening programs now offer women with dense breasts a screening ultrasound or an annual mammogram.
The Dense Tissue and Early Breast Neoplasm Screening (DENSE) trial is a randomized, controlled trial that is investigating the use of MRI as a supplementary imaging modality in women with extremely dense breasts. While previous studies have demonstrated that MRI can increase the sensitivity of breast cancer detection compared to mammography. The primary objective of the DENSE trial is to investigate whether MRI can improve early detection and reduce the interval cancer rate.
The trial enrolled more than 40,000 women with extremely dense breasts and negative results on mammography; over 4,700 of those women underwent supplemental imaging with MRI in the first screening round.
Figure 1: Flowchart. DENSE investigated the effectiveness of screening with mammography plus MRI compared to mammography alone (1:4 ratio) in women age 50 – 75 with extremely dense breasts (ACR 4) in a prospective, parallel-group, randomized, controlled, multicenter trial in the Dutch biennial screening program. Three consecutive screening rounds are performed (1st round prevalence, 2nd and 3rd round incidence) 1
Gadovist® Contrast-Enhanced MRI Cuts Interval Cancers in Half
Results of 1st screening round:
Table 1 Secondary endpoint screening-detected cancer. Recall rate: Women with MRI for which follow-up diagnostic procedures were necessary (imaging or biopsy)
|MRI Screening Participants||No./Total||Rate (95% CI)|
|Breast Cancers detected||79/4,783||16.5/1,000 (13.1-20.5)|
|Recall Rate||454/4,783||94.9/1,000 (86.9-103.6)|
|Supplemental MRI in first screening round detected 16.5/1,000 additional cancers after negative mammography 3|
Table 2 Primary endpoint interval cancer rate assessed during 2-year follow-up after 1st MRI, ITT: Intention to treat (all woman invited for MRI) MRI participants: 59% who accepted invitation to MRI
Interval cancer rate per 1,000
|Control arm Mammography only||Intervention arm
Invitation to MRI with Gadovist®
|Offering supplemental MRI screening with Gadovist® in women with extremely dense breasts results in 50% less interval cancers 3|
Dr. Barkhausen discusses results from the GEMMA study and how contrast-enhanced MRI was found to compare to mammography for all patient groups.
Dr. Kuhl Discusses the concept of abbreviated breast MRI protocols and how they can reduce cost and increase availability of MRI for breast cancer screening.
Dr. Van Gils Discusses initial results from the DENSE trial, personalized screening and the utility of MRI for women with extremely dense breast tissue.
Dr. Kuhl discusses re-thinking breast cancer screening and abbreviated breast MRI
Dr. Mann and Dr. Sardanelli discuss risk adjusted breast screening strategies
Dr. Van Gils discusses additional MRI screening in women with extremely dense breasts:
1 Sprague BL, Gangnon RE, Burt V, et al. Prevalence of mammographically dense breasts in the United States. J Natl Cancer Inst. 2014:12;106(10).
2 Emaus MJ, Bakker MF, Peeters PH, et al. MR Imaging as an Additional Screening Modality for the Detection of Breast Cancer in Women Aged
50-75 Years with Extremely Dense Breasts: The DENSE Trial Study Design. Radiology. 2015;277(2):527 – 537.
3 Bakker MF, de Lange SV, Pijnappel RM, et al. Supplemental MRI Screening for Women with Extremely Dense Breast Tissue. N Engl J Med. 2019; .
4 Dense Breast Canada website: https://densebreastscanada.ca/faq/ (accessed October 6, 2020)