University of Oulu

Sassi, A., Salminen, A., Jukkola, A. et al. Breast density and the likelihood of malignant MRI-detected lesions in women diagnosed with breast cancer. Eur Radiol 33, 8080–8088 (2023).

Breast density and the likelihood of malignant MRI-detected lesions in women diagnosed with breast cancer

Saved in:
Author: Sassi, Antti1,2; Salminen, Annukka1,2; Jukkola, Arja2,3;
Organizations: 1Department of Radiology, Tampere University Hospital, Elämänaukio 1, 33520, Tampere, Finland
2Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
3Department of Oncology, Tays Cancer Center, Tampere University Hospital, Tampere, Finland
4Department of Surgery, Tampere University Hospital, Tampere, Finland
5Research Unit of Medical Imaging Physics and Technology, University of Oulu, Oulu, Finland
6Department of Radiology, Oulu University Hospital, Oulu, Finland
7Department of Pathology, Fimlab Laboratories, Tampere University Hospital, Tampere, Finland
8Faculty of Social Sciences, Tampere University, Tampere, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1 MB)
Persistent link:
Language: English
Published: Springer Nature, 2023
Publish Date: 2023-10-27


Objectives: To assess whether mammographic breast density in women diagnosed with breast cancer correlates with the total number of incidental magnetic resonance imaging (MRI)-detected lesions and the likelihood of the lesions being malignant.

Methods: Patients diagnosed with breast cancer meeting the EUSOBI and EUSOMA criteria for preoperative breast MRI routinely undergo mammography and ultrasound before MRI at our institution. Incidental suspicious breast lesions detected in MRI are biopsied. We included patients diagnosed with invasive breast cancers between 2014 and 2019 who underwent preoperative breast MRI. One reader retrospectively determined breast density categories according to the 5th edition of the BI-RADS lexicon.

Results: Of 946 patients with 973 malignant primary breast tumors, 166 (17.5%) had a total of 175 (18.0%) incidental MRI-detected lesions (82 (46.9%) malignant and 93 (53.1%) benign). High breast density according to BI-RADS was associated with higher incidence of all incidental enhancing lesions in preoperative breast MRIs: 2.66 (95% confidence interval: 1.03–6.86) higher for BI-RADS density category B, 2.68 (1.04–6.92) for category C, and 3.67 (1.36–9.93) for category D compared to category A (p < 0.05). However, high breast density did not predict higher incidence of malignant incidental lesions (p = 0.741). Incidental MRI-detected lesions in the contralateral breast were more likely benign (p < 0.001): 18 (27.3%)/48 (72.7%) vs. 64 (58.7%)/45 (41.3%) malignant/benign incidental lesions in contralateral vs. ipsilateral breasts.

Conclusion: Women diagnosed with breast cancer who have dense breasts have more incidental MRI-detected lesions, but higher breast density does not translate to increased likelihood of malignant incidental lesions.

Clinical relevance statement: Dense breasts should not be considered as an indication for preoperative breast MRI in women diagnosed with breast cancer.

Key points: • The role of preoperative MRI of patients with dense breasts diagnosed with breast cancer is under debate. • Women with denser breasts have a higher incidence of all MRI-detected incidental breast lesions, but the incidence of malignant MRI-detected incidental lesions is not higher than in women with fatty breasts. • High breast density alone should not indicate preoperative breast MRI.

see all

Series: European radiology
ISSN: 0938-7994
ISSN-E: 1432-1084
ISSN-L: 0938-7994
Volume: 33
Issue: 11
Pages: 8080 - 8088
DOI: 10.1007/s00330-023-10072-w
Type of Publication: A1 Journal article – refereed
Field of Science: 3122 Cancers
217 Medical engineering
Funding: Antti Sassi received funding for this study from the Emil Aaltonen Foundation. This study was partly financially supported by the research funding provided by Tampere University Hospital (Project No. MJ006L) and by the Competitive State Research Financing of the Expert Responsibility Area of Tampere University Hospital (Project No. 9AC002).
Copyright information: © The Author(s) 2023. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit