Locally Advanced Breast Cancer Treated with Primary Chemotherapy: Comparison between Magnetic Resonance Imaging and Pathologic Evaluation of Residual Disease

Abstract

Aims and Background We evaluated the response of locally advanced breast cancer to induction chemotherapy using MRI techniques. The size and vitality of any residual pathologic tissue was quantified by means of morphologic and dynamic analysis. A curve derived from the dynamic parameters shows the uptake intensity with respect to the time elapsed since administration, which is related to vascularization and therefore indirectly reflects the angiogenesis of malignant tissue. Methods and Study Design A group of 30 patients were examined with MRI for staging purposes before undergoing treatment and subsequently to assess the response to treatment. Alterations in size and dynamic parameters were closely monitored. Results The overall accuracy was 90%, the sensitivity 96%, the specificity 75%, the positive predictive value 92.5% and the negative predictive value 66%. Interestingly, analysis of the dynamic curves made it possible to obtain additional information regarding the angiogenetic activity of the residual tumor. Conclusions Evaluation of the response to treatment by means of conventional imaging and clinical examination can be particularly difficult because of the fibrosis induced by cytotoxic drugs or the small volume of residual disease. The additional information supplied by MRI could therefore allow a more conservative surgical approach in selected cases of optimal response to treatment, as well as a much more accurate follow-up. Furthermore, the variation in dynamic parameters according to the vitality of residual disease could in the future become a useful tool for monitoring the effectiveness of anti-angiogenetic drugs.