Association between breast cancer, breast density, and body adiposity evaluated by MRI

Abstract

Objective Despite the lack of reliable methods with which to measure breast density from 2D mammograms, numerous studies have demonstrated a positive association between breast cancer and breast density. The goal of this study was to study the association between breast cancer and body adiposity, as well as breast density quantitatively assessed from 3D MRI breast images. Methods Breast density was calculated from 3D T1-weighted MRI images. The thickness of the upper abdominal adipose layer was used as a surrogate marker for body adiposity. We evaluated the correlation between breast density, age, body adiposity, and breast cancer. Results Breast density was calculated for 410 patients with unilateral invasive breast cancer, 73 patients with DCIS, and 361 controls without breast cancer. Breast density was inversely related to age and the thickness of the upper abdominal adipose layer. Breast cancer was only positively associated with body adiposity and age. Conclusion Age and body adiposity are predictive of breast density. Breast cancer was not associated with breast density; however, it was associated with the thickness of the upper abdominal adipose layer, a surrogate marker for body adiposity. Our results based on a limited number of patients warrant further investigations.

Invasive Breast Cancer Preferably and Predominantly Occurs at the Interface Between Fibroglandular and Adipose Tissue

“…A total of 294 consecutive patients diagnosed with unilateral invasive breast cancer with pre-treatment breast DCE-MRI performed from October 2008 to December 2014 in our outpatient center were identified by MRI reports and the corresponding medical records. MRI breast density measurements for these patients have been previously reported 21 . The indication for breast DCE-MRI was for the evaluation of disease extent and treatment planning following a biopsy-proven invasive breast cancer diagnosis for a majority of these patients (276, 94%).…”

“…The thickness of the UAAL, a surrogate marker for body adiposity, ranged from 1 to 37 mm. The MRI breast density of these patients was calculated from the T 1 -weighted pre-contrast images, as described earlier 21 . The density ranged from very dense at 80.7% to very fatty at 3.2%.…”

“…Three-dimensional MRI breast density was calculated from the contralateral breast with no tumor from the pre-contrast T 1 -weighted images without fat saturation as described 21 . Briefly, bright fatty tissue and the entire breast were segmented by thresholding separately after the correction of image intensity bias artifacts due to magnetic field heterogeneity.…”

“…Percent fatty tissue density was calculated as the percentage of total voxel counts occupied by the fatty tissues divided by that of the entire breast. The MRI percent breast density was calculated as the remaining percentage of the fatty tissue 21 .…”

“…This thickness was used as a surrogate marker for body adiposity due to a lack of body mass index information in this retrospective study 21 .…”