Published in:
Open Access 01-02-2017 | Epidemiology
Volumetric breast density affects performance of digital screening mammography
Published in: Breast Cancer Research and Treatment | Issue 1/2017
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Purpose
To determine to what extent automatically measured volumetric mammographic density influences screening performance when using digital mammography (DM).
Methods
We collected a consecutive series of 111,898 DM examinations (2003–2011) from one screening unit of the Dutch biennial screening program (age 50–75 years). Volumetric mammographic density was automatically assessed using Volpara. We determined screening performance measures for four density categories comparable to the American College of Radiology (ACR) breast density categories.
Results
Of all the examinations, 21.6% were categorized as density category 1 (‘almost entirely fatty’) and 41.5, 28.9, and 8.0% as category 2–4 (‘extremely dense’), respectively. We identified 667 screen-detected and 234 interval cancers. Interval cancer rates were 0.7, 1.9, 2.9, and 4.4‰ and false positive rates were 11.2, 15.1, 18.2, and 23.8‰ for categories 1–4, respectively (both p-trend < 0.001). The screening sensitivity, calculated as the proportion of screen-detected among the total of screen-detected and interval tumors, was lower in higher density categories: 85.7, 77.6, 69.5, and 61.0% for categories 1–4, respectively (p-trend < 0.001).
Conclusions
Volumetric mammographic density, automatically measured on digital mammograms, impacts screening performance measures along the same patterns as established with ACR breast density categories. Since measuring breast density fully automatically has much higher reproducibility than visual assessment, this automatic method could help with implementing density-based supplemental screening.