Purpose: The aim of this study is to give an overview on the surveillance of response to neoadjuvant chemotherapy in locally advanced breast cancer with mammography, ultrasound and breast MRI.
Material and methods: The results of a recently presented study on surveillance in the course of chemotherapy with contrast-enhanced MRI are compared with ratings based on mammography and ultrasound.
Results: Contrast-enhanced MRI correlates best with the histological tumor size when compared with mammography and ultrasound. Tumors with a high HER2 score (2+ with positive FISH test or 3+) show a significantly higher response compared to tumors with a lower HER2 score: size p <0.01, maximum enhancement p <0.01 and area under the curve (AUC) p <0.05. Reduction of tumor size and enhancement are complementary parameters and are not correlated to each other (r=0.22).
Discussion: Contrast-enhanced MRI of the breast is a reliable method for quantification of the response to neoadjuvant chemotherapy. The reductions of tumor size and of tumor enhancement are not correlated. Therefore, it may be reasonable to take both aspects for quantification of therapy response into account. Further studies are needed for evaluation of the value of breast MRI as a prognostic factor.