Purpose: Tumor grading (TG) is one of the most widely used prognostic factors in the case of breast cancer. This study aims to identify the potential of magnetic resonance mammography (MRM) to non-invasively assess TG.
Materials and methods: 399 invasive breast cancers were included (IRB approval; standardized clinical MRM protocols). All breast cancers were prospectively evaluated by two experienced (> 500 MRM) and blinded radiologists in consensus. In every cancer a set of 18 previously published MRM descriptors was assessed. These were assessed by univariate and multivariate analysis to identify the potential of MRM to predict TG (X2 statistics; binary logistic regression; area under the ROC curve [AUC]).
Results: 8 of 18 MRM descriptors were associated with TG, e. g. internal structure, edema (p < 0.001), as well as skin thickening and destruction of the nipple line (p < 0.05). MRM was feasible to predict TG by multivariate analysis (p < 0.001). The highest potential could be identified to predict well differentiated breast cancers with good prognosis (AUC = 0.930).
Conclusion: MR mammography was able to non-invasively assess tumor grading in a standard protocol. Since tumor grading is a surrogate for overall survival, these results provide further evidence to the clinical application of MR mammography as a noninvasive prognostic tool.
© Georg Thieme Verlag KG Stuttgart · New York.