Radiological predictive factors on preoperative multimodality imaging are related to Oncotype DX recurrence score in estrogen-positive/human epidermal growth factor receptor 2-negative invasive breast cancer: a cross-sectional study

OBJECTIVE

The Oncotype DX (ODX) estimates the 10-year risk of metastasis or recurrence of breast cancer and indicates whether chemotherapy is likely to be effective; however, the high cost of this test may limit its use for patients. The aim of this study was to evaluate the potential of preoperative imaging using mammography (MMG), ultrasonography (US), and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and positron emission tomography/computed tomography (PET/CT) metabolic parameters in predicting the ODX recurrence score (ODXRS), which prognosticates estrogen receptor-positive (ER +)/human epidermal growth factor receptor 2-negative (HER2-) breast cancer.

METHODS

This retrospective study was conducted on 51 patients with ER+/ HER2- early-stage breast cancer with preoperative images available. Surgical specimens were sent for ODX assay and the ODXRS was categorized as low (<18) or intermediate/high (≥18). MMG/US findings were classified according to BI-RADS categories. For MRI analysis, tumor growth orientation was evaluated in addition to morphological assessment in BI-RADS. For PET/CT analysis, standardized uptake value (SUV) of the tumor were measured. Patient, tumor, and image characteristics were compared between the two groups, and predictors of the low ODXRS group were determined by logistic regression analysis. Two-sided P values less than 0.05 were considered statistically significant.

RESULTS

Thirty-two (63%) and 19 (37%) patients were categorized as low and intermediate/high ODXRS, respectively. On univariate analysis, nuclear grade, tumor margin, and tumor growth orientation on MRI, and SUV_max on PET/CT were significantly associated with a low ODXRS. Multivariate analysis revealed that tumor growth orientation perpendicular to the Cooper's ligament on MRI (P = 0.031) and a low SUV_max on PET/CT (P = 0.016) were independent prognostic factors for a low ODXRS. As a predictor of low ODXRS, the receiver operating characteristic (ROC) analysis of the SUV_max showed that using 3.0 as the optimal cut-off value has a sensitivity and specificity of 94.4% and 73.0%, respectively, with an area under the curve (AUC) of 0.923.

CONCLUSIONS

The combination of perpendicular tumor growth orientation to Cooper's ligaments on MRI and a low SUV_max on PET/CT may predict a low ODXRS.

The Spatial Relationship of Malignant and Benign Breast Lesions with Respect to the Fat-Gland Interface on Magnetic Resonance Imaging

The fat-gland interface in the breast is noteworthy in that major vessels and lymphatic channels supplying the breast are located there; however, the relationship between breast lesion formation and the fat-gland interface is poorly understood. Here we evaluate the location of malignant and benign breast lesions with respect to the fat-gland interface in 881 women 50 years of age and younger, utilizing MR imaging. We find that most breast lesions are located in or near the interface in qualitative (89.7%) and quantitative (90.0%, 1 cm within the interface) analyses. This propensity for the fat-gland interface is not accounted for by breast anatomy, whereby 12.3% and 55.7% of breast volume is within 2 mm and 1 cm of the interface, respectively. Malignant lesions were located in or near the interface in significantly higher proportions than benign lesions in qualitative (94.3% vs. 67.3%, P < 0.001) and quantitative (49.7% vs. 34.5%, P < 0.001, 2 mm within the interface) analyses. This phenomenon may reflect a biological importance of the fat-gland interface in breast cancer development and progression.

Anisotropic Properties of Breast Tissue Measured by Acoustic Radiation Force Impulse Quantification

The goal of our study was to investigate the anisotropy of normal breast glandular and fatty tissue with acoustic radiation force impulse (ARFI) quantification. A total of 137 breasts in 137 women were enrolled. These breasts were divided into the duct-apparent group and the duct-inapparent group, divided into the ligament-apparent group and the ligament-inapparent group. Shear wave velocity (SWV) in the radial (SWV(r)) and anti-radial (SWV(a-r)) directions was measured. The elastic anisotropy of glandular tissue and fatty tissue was evaluated as the ratio between SWV(r) and SWV(a-r). The SWV ratio was 1.30 ± 0.45 for glandular tissue and 1.27 ± 0.53 for fatty tissue in the total group. In glandular tissue, the SWV ratio of the duct-apparent group was higher than that of the duct-inapparent group (p = 0.011). In both glandular and fatty tissue, the SWV ratio was higher in the ligament-apparent group than in the ligament-inapparent group (p < 0.05 for both). SWV(r) was higher than SWV(a-r) in both glandular tissue and fatty tissue in all groups (p < 0.05 for all) except in breast fatty tissue in the ligament-inapparent group (p = 0.913). It is concluded that both breast glandular tissue and fatty tissue exhibited anisotropy of elastic behavior. To improve the diagnostic power of elastography in breast lesions, the elastic anisotropy of glandular tissue and fatty tissue should be taken into account in calculating strain ratio or elasticity ratio.

Bioelectrical Impedance Methods for Noninvasive Health Monitoring: A Review

Under the alternating electrical excitation, biological tissues produce a complex electrical impedance which depends on tissue composition, structures, health status, and applied signal frequency, and hence the bioelectrical impedance methods can be utilized for noninvasive tissue characterization. As the impedance responses of these tissue parameters vary with frequencies of the applied signal, the impedance analysis conducted over a wide frequency band provides more information about the tissue interiors which help us to better understand the biological tissues anatomy, physiology, and pathology. Over past few decades, a number of impedance based noninvasive tissue characterization techniques such as bioelectrical impedance analysis (BIA), electrical impedance spectroscopy (EIS), electrical impedance plethysmography (IPG), impedance cardiography (ICG), and electrical impedance tomography (EIT) have been proposed and a lot of research works have been conducted on these methods for noninvasive tissue characterization and disease diagnosis. In this paper BIA, EIS, IPG, ICG, and EIT techniques and their applications in different fields have been reviewed and technical perspective of these impedance methods has been presented. The working principles, applications, merits, and demerits of these methods has been discussed in detail along with their other technical issues followed by present status and future trends.