Differential impact of body mass index on absolute and percent breast density: implications regarding their use as breast cancer risk biomarkers

作者：Schetter Susann E; Hartman Terryl J; Liao Jason; Richie John P; Prokopczyk Bogdan; DuBrock Cindy; Signori Carina; Hamilton Christopher; Demers Laurence M; El Bayoumy Karam; Manni Andrea^*

来源：Breast Cancer Research and Treatment, 2014, 146(2): 355-363.

DOI：10.1007/s10549-014-3031-6

• Percent versus absolute breast density
• Breast density and BMI
• Dietary variables and breast density
• Physical activity and breast density

Percent breast density (PBD), a commonly used biomarker of breast cancer risk (BCR), is confounded by the influence of non-dense breast tissue on its measurement and factors, such as BMI, which have an impact on non-dense tissue. Consequently, BMI, a potent BCR factor, is, paradoxically, negatively correlated with PBD. We propose that absolute breast density (ABD) is a more accurate biomarker of BCR. We used a volumetric method to compare the correlation between PBD and ABD with baseline demographics and dietary and physical activity variables in a group of 169 postmenopausal women enrolled in a clinical trial prior to any intervention. As expected, a strong negative correlation between PBD and BMI was observed (Rho = -0.5, p < 5e(-12)). In contrast, we observed a strong, previously not well established, positive correlation of BMI with ABD (Rho = 0.41, p < 2.5e(-8)), which supports the use of ABD as a more accurate indicator of BCR. Correction of PBD by BMI did not frequently provide the same information as ABD. In addition, because of the strong influence of BMI on ABD, many correlations between dietary variables and ABD did not emerge, until adjustment was made for BMI. ABD corrected by BMI should be the gold standard BD measurement. These findings identify the optimal measurement of BD when testing the influence of an intervention on BD as a biomarker of BCR.

• 出版日期2014-7