Can diffusion-weighted MR imaging and contrast-enhanced MR imaging precisely evaluate and predict pathological response to neoadjuvant chemotherapy in patients with breast cancer?
Adjuvant systemic chemotherapy has been shown to prolong survival in all subsets of patients with breast cancer. In addition, among patients with locally advanced breast cancer, neoadjuvant orpreoperative chemotherapy has improved the ability to perform breast-conserving therapy. This observation, combined with multiple preclinical hypotheses and the results of laboratory studies, has prompted investigation of neoadjuvant chemotherapy as a treatment strategy for operable breast cancer. In this article, both the evidence supporting this treatment approach and some of the problems associated with it are reviewed. Currently, seven randomized studies comparing neoadjuvant chemotherapy followed by surgery or surgery followed, in turn, by adjuvant chemotherapy have been completed and their results analyzed. Despite exciting preclinical evidence, no trial to date has shown a survival advantage for the neoadjuvant treatment approach. Nonetheless, evidence from more recent phase III trials and the fact that neoadjuvant chemotherapy is not harmful topatients validate its use in operable breast cancer.