Prognostic Role of MRI Enhancement Features in Patients With Breast Cancer: Value of Adjacent Vessel Sign and Increased Ipsilateral Whole-Breast Vascularity

OBJECTIVE. The purpose of this study was to compare adjacent vessel sign, increased ipsilateral whole-breast vascularity, and various MRI features as described in the American College of Radiology BI-RADS MRI lexicon with histopathologic predictors in patients with unilateral breast cancer. MATERIALS AND METHODS. We retrospectively evaluated breast MRI examinations of 249 patients with histologically confirmed breast cancer. In addition to the BI-RADS MRI lexicon, the adjacent vessel sign and increased ipsilateral whole-breast vascularity of the cancer-bearing breast were evaluated by two independent observers. MRI features were then correlated with histopathologic prognostic factors. RESULTS. The adjacent vessel sign was significantly (p = 0.023 to p < 0.001) associated with tumor size, lymph node metastasis, distant metastasis, nuclear grade, and expression of estrogen and progesterone receptors. Increased ipsilateral whole-breast vascularity was significantly associated with all histopathologic predictors (p = 0.017 to p < 0.001). In multivariate analysis, the significant and independent predictors were a spiculated margin and rim enhancement for negative estrogen and progesterone receptors, a kinetic curve type for higher histologic grade, and an increased ipsilateral whole-breast vascularity for larger tumor size, lymph node metastasis, distant metastasis, higher nuclear grade, and higher histologic grade. CONCLUSION. In conjunction with the standard BI-RADS MRI lexicon, the adjacent vessel sign and increased ipsilateral whole-breast vascularity may serve as additional predictors of a poor prognosis.