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Temporal changes in mammographic breast density and breast cancer risk among women with benign breast disease.pdf (789.16 kB)

Temporal changes in mammographic breast density and breast cancer risk among women with benign breast disease

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posted on 2024-05-02, 08:28 authored by Maeve MulloolyMaeve Mullooly, Shaoqi Fan, Ruth M Pfeiffer, Erin Aiello Bowles, Maire A. Duggan, Roni T Falk, Kathryn Richert-Boe, Andrew G Glass, Teresa M Kimes, Jonine D Figueroa, Thomas E Rohan, Mustapha Abubakar, Gretchen L Gierach

Introduction: Benign breast disease (BBD) and high mammographic breast density (MBD) are prevalent and independent risk factors for invasive breast cancer. It has been suggested that temporal changes in MBD may impact future invasive breast cancer risk, but this has not been studied among women with BBD.

Methods: We undertook a nested case-control study within a cohort of 15,395 women with BBD in Kaiser Permanente Northwest (KPNW; 1970-2012, followed through mid-2015). Cases (n = 261) developed invasive breast cancer > 1 year after BBD diagnosis, whereas controls (n = 249) did not have breast cancer by the case diagnosis date. Cases and controls were individually matched on BBD diagnosis age and plan membership duration. Standardized %MBD change (per 2 years), categorized as stable/any increase (≥ 0%), minimal decrease of less than 5% or a decrease greater than or equal to 5%, was determined from baseline and follow-up mammograms. Associations between MBD change and breast cancer risk were examined using adjusted unconditional logistic regression.

Results: Overall, 64.5% (n = 329) of BBD patients had non-proliferative and 35.5% (n = 181) had proliferative disease with/without atypia. Women with an MBD decrease (≤ - 5%) were less likely to develop breast cancer (Odds Ratio (OR) 0.64; 95% Confidence Interval (CI) 0.38, 1.07) compared with women with minimal decreases. Associations were stronger among women ≥ 50 years at BBD diagnosis (OR 0.48; 95% CI 0.25, 0.92) and with proliferative BBD (OR 0.32; 95% CI 0.11, 0.99).

Discussion: Assessment of temporal MBD changes may inform risk monitoring among women with BBD, and strategies to actively reduce MBD may help decrease future breast cancer risk.


Intramural Research Funds of the Division of Cancer Epidemiology and Genetics (DCEG) of the National Cancer Institute, Department of Health and Human Services, USA

National Cancer Institute R50CA211115

Health Research Board in Ireland (Emerging Investigator Award EIA‑2019‑012)

Breast Cancer Research Foundation (BCRF‑22‑140)


Data Availability Statement

The data that support these findings are not publicly available because they contain information that could compromise research participant privacy and confidentiality. The authors will make the data available upon reasonable request and with the permission of the Kaiser Permanente Center for Health Research in Portland, Oregon.


The original article is available at

Published Citation

Mullooly M. et al. Temporal changes in mammographic breast density and breast cancer risk among women with benign breast disease. Breast Cancer Res. 2024;26(1):52

Publication Date

26 March 2024

PubMed ID



  • Public Health and Epidemiology
  • School of Population Health


Biomed Central


  • Published Version (Version of Record)

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