Vachon Celine M, Fowler Erin Ee, Tiffenberg Gail, Scott Christopher G, Pankratz V Shane, Sellers Thomas A, Heine John J
Breast Cancer Res. 2013 Jan 4;15(1):R1. doi: 10.1186/bcr3372.
Mammographic density has been established as a strong risk factor for breast cancer, primarily using digitized film mammograms. Full-field digital mammography (FFDM) is replacing film mammography, has different properties than film, and provides both raw and processed clinical display representation images. We evaluated and compared FFDM raw and processed breast density measures and their associations with breast cancer.
A case-control study of 180 cases and 180 controls matched by age, postmenopausal hormone use, and screening history was conducted. Mammograms were acquired from a General Electric Senographe 2000D FFDM unit. Percent density (PD) was assessed for each FFDM representation using the operator-assisted Cumulus method. Reproducibility within image type (n = 80) was assessed using Lin's concordance correlation coefficient (rc). Correlation of PD between image representations (n = 360) was evaluated using Pearson's correlation coefficient (r) on the continuous measures and the weighted kappa statistic (κ) for quartiles. Conditional logistic regression was used to estimate odds ratios (ORs) for the PD and breast cancer associations for both image representations with 95% confidence intervals. The area under the receiver operating characteristic curve (AUC) was used to assess the discriminatory accuracy.
Percent density from the two representations provided similar intra-reader reproducibility (rc= 0.92 for raw and rc= 0.87 for processed images) and was correlated (r = 0.82 and κ = 0.64). When controlling for body mass index, the associations of quartiles of PD with breast cancer and discriminatory accuracy were similar for the raw (OR: 1.0 (ref.), 2.6 (1.2 to 5.4), 3.1 (1.4 to 6.8), 4.7 (2.1 to 10.6); AUC = 0.63) and processed representations (OR: 1.0 (ref.), 2.2 (1.1 to 4.1), 2.2 (1.1 to 4.4), 3.1 (1.5 to 6.6); AUC = 0.64).
Percent density measured with an operator-assisted method from raw and processed FFDM images is reproducible and correlated. Both percent density measures provide similar associations with breast cancer.
乳房X线密度已被确认为乳腺癌的一个重要危险因素，主要基于数字化乳腺钼靶照片。全视野数字化乳腺摄影（FFDM）正在取代乳腺钼靶摄影，其特性与胶片不同，可提供原始和处理后的临床显示图像。我们评估并比较了FFDM原始图像和处理后图像的乳房密度测量值及其与乳腺癌的关联。
开展了一项病例对照研究，纳入180例病例和180例对照，根据年龄、绝经后激素使用情况和筛查史进行匹配。乳房X线照片由通用电气Senographe 2000D FFDM设备采集。使用操作员辅助的积云法评估每个FFDM图像的密度百分比（PD）。使用林氏一致性相关系数（rc）评估图像类型内（n = 80）的可重复性。对于连续测量值，使用皮尔逊相关系数（r）评估图像表示之间的PD相关性（n = 360），对于四分位数，使用加权kappa统计量（κ）评估。采用条件逻辑回归估计两种图像表示的PD与乳腺癌关联的比值比（OR）及95%置信区间。采用受试者工作特征曲线下面积（AUC）评估鉴别准确性。
两种图像表示的密度百分比在阅片者内具有相似的可重复性（原始图像rc = 0.92，处理后图像rc = 0.87）且具有相关性（r = 0.82，κ = 0.64）。在控制体重指数后，原始图像（OR：1.0（参照），2.6（1.2至5.4），3.1（1.4至6.8），4.7（2.1至10.6）；AUC = 0.63）和处理后图像（OR：1.0（参照），2.2（1.1至4.1），2.2（1.1至4.4），3.1（1.5至6.6）；AUC = 0.64）的PD四分位数与乳腺癌的关联及鉴别准确性相似。
使用操作员辅助方法从FFDM原始图像和处理后图像测量的密度百分比具有可重复性且相关。两种密度百分比测量值与乳腺癌的关联相似。
