Mammographic breast density over time among women who have participated in BreastScreen Norway
Journal article, Peer reviewed
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Original versionMoshina N, Waade GG, Roman M, Sebuødegård S, Hofvind S. Mammographic breast density over time among women who have participated in BreastScreen Norway. Progress in Biomedical Optics and Imaging. 2018;10718 http://dx.doi.org/10.1117/12.2317927
Background: We analyzed the consistency in absolute and percent density using an automated method for estimating volumetric breast density among women who attended BreastScreen Norway 2007-2015. Material and Methods: We used information from 33,711 women aged 50-69 who underwent two to five full field digital screening examinations biennially, 2007-2015. BMI and HT-use was obtained from a self-administered questionnaire, sent together with the invitation to screening. BMI was categorized into <21.0; 21.0-24.9; ≥25.0 kg/m2, while use of HT was defined as ever versus never used. An automated method estimated fibroglandular volume (cm3), breast volume (cm3) and volumetric breast density (%) for each screening examination. We applied mixed-effects linear models to estimate associations between age, fibroglandular volume, breast volume and volumetric breast density over time including data on BMI and HT. Results: The results models indicated age to be associated with decreased fibroglandular volume and volumetric breast density, and increased breast volume. BMI <21 kg/m2 was associated with higher volumetric breast density, but lower fibroglandular and breast volume. Contrary, BMI ≥25 kg/m2 was associated with lower volumetric breast density and higher fibroglandular and breast volumes. Variation in volumetric breast density and fibroglandular volume within women was rather subtle: this variance did not exceed 10% for either volumetric breast density, fibroglandular volume or breast volume. Conclusion: Automated measures of volumetric breast density and fibroglandular volume software decreased with age among women screened in BreastScreen Norway. Absolute and percent density varied with a maximum of 10% over time, from first to last screening examination.