From the Department of Breast Medical Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX
Authors’ disclosures of potential conflicts of interest are found at the end of this article.
Address reprint requests to Vicente Valero, MD, FACP, Department of Breast Medical Oncology, Unit 1354, University of Texas M.D. Anderson Cancer Caner, P.O. Box 301439, Houston, TX 77230-1439; e-mail: vvalero{at}mdanderson.org
Overview: Neoadjuvant therapy is the initial component of the multidisciplinary approach for the treatment of patients with locally advanced and large, operable breast cancer. Neoadjuvant therapy is safe and as effective as adjuvant therapy. However, it increases the breast-conservative surgery rate and provides an early surrogate factor, pathological complete response (pCR), for long-term outcome and an in vivo model for understanding breast cancer biology. Patients who obtain breast and axillary pCR after neoadjuvant chemotherapy have a markedly improved disease-free survival and overall survival relative to those with residual disease (RD), even those patients with estrogen and/or progesterone receptor-positive breast cancer. The proportion of patients who achieve a pCR and who, therefore, have an expectation of an excellent outcome is only 10% to 30%. However, in a new pathological classification, patients with minimal residual cancer burden (RCB-1) have outcomes similar to those with pCR (RCB-0). Finally, microarray gene signatures may allow patients with RD to be dichotomized as those with favorable compared with poor prognosis. New agents based in novel therapeutic targets are needed for patients with RD after neoadjuvant therapy.
