Ag silver Az area under the receiver operating characteristic curve BI-RADS Breast Imaging Reporting and Data System (American College of Radiology) BMI body mass index BTE breast tissue equivalent CI(s) confidence interval(s) D unit DBT unit DBT digital breast tomosynthesis FAST automated self-adjusting Tilt Compression Paddle (Hologic, Inc., Bedford, MA) FFDM full-field digital mammography H unit 2D unit HRT hormone replacement therapy Rationale and Objectives: Mammographic density is an important risk factor for breast cancer, but translation to the clinic requires assurance that prior work based on mammography is applicable to current technologies. The purpose of this work is to evaluate whether a calibration methodology developed previously produces breast density metrics predictive of breast cancer risk when applied to a caseÀcontrol study. Materials and Methods: A matched case control study (n = 319 pairs) was used to evaluate two calibrated measures of breast density. Two-dimensional mammograms were acquired from six Hologic mammography units: three conventional Selenia two-dimensional full-field digital mammography systems and three Dimensions digital breast tomosynthesis systems. We evaluated the capability of two calibrated breast density measures to quantify breast cancer risk: the mean (PG m) and standard deviation (PG sd) of the calibrated pixels. Matching variables included age, hormone replacement therapy usage/duration, screening history, and mammography unit. Calibrated measures were compared to the percentage of breast density (PD) determined with the operator-assisted Cumulus method. Conditional logistic regression was used to generate odds ratios (ORs) from continuous and quartile (Q) models with 95% confidence intervals. The area under the receiver operating characteristic curve (Az) was also used as a comparison metric. Both univariate models and models adjusted for body mass index and ethnicity were evaluated.