Comparison of Different Dynamic Contrast Enhanced-Magnetic Resonance Imaging Descriptors and Clinical Findings Among Breast Cancer Subtypes Determined Based on Molecular Assessment

Breast cancer is a heterogeneous disease with different molecular and histologic subtypes, clinical behaviors and prognosis. The same stage of disease and similar histopathological characteristics may show different treatment responses. Identification of breast cancer subtypes has become important for planning the targeted therapy and personalized management of patients. To compare the clinicopathologic findings, dynamic contrast enhanced-magnetic resonance imaging (DCE-MRI) characteristics and associated MRI findings among breast cancer molecular subtypes. Patients and Methods: 267 pathologically proven invasive breast cancers in 263 patients were included. Clinicopathological findings, DCE-MRI findings and associated MRI findings were retrospectively evaluated and compared among breast cancer subtypes. Invasive ductal carcinoma was the most common histological tumor type (87.6%). There were 222 (83.1%) masses and 45 (16.9%) non-mass enhancements. The molecular subtypes were luminal A in 174 (65.1%), luminal B in 45 (16.9%), human epidermal growth factor receptor 2 (HER2) positive in 24 (9%) and triple negative (TN) in 24 (9%) of the lesions. Spiculated mass margin was significantly associated with luminal A breast cancer (45.2%) and irregular shape was significantly more common in luminal A (86.3%) and luminal B lesions (95.1%) (P < 0.001). Larger mass size (P = 0.027), non-mass enhancement (P = 0.005), perilesional + prepectoral edema and skin + perilesional + prepectoral edema were significantly associated with HER2 positive breast cancer (P = 0.001). Higher histological grade, oval mass shape, circumscribed mass margin, intratumoral high/very high signal intensity on T2 weighted image (T2WI) were significantly associated with TN breast cancer (P < 0.001). Histological grade, size and morphological features of masses on DCE-MRI, intratumoral signal intensity on T2WI and edema pattern would be helpful to distinguish breast cancer subtypes.