Neoadjuvant therapy for breast cancer: assessing treatment progress and managing poor responders.

There is no clear consensus regarding the most effective management of poor responders to neoadjuvant chemotherapy. Intensifying or changing primary systemic treatment has not been shown to offer any benefit. There is a paucity of trials testing the utility of adjuvant chemotherapy in this setting. Adjuvant hormonal treatment significantly decreases relapse rates in patients with estrogen receptor-positive breast cancer, regardless of initial response to chemotherapy. Neoadjuvant hormonal therapy is usually reserved for patients who are not candidates for chemotherapy or surgery. In patients with HER-2-overexpressing tumors who are candidates for chemotherapy, trastuzumab improves outcomes when administered in the preoperative or postoperative setting. This article examines issues related to the assessment of response to preoperative therapy and the clinical use of these assessments. It reviews important clinical evidence related to the utility of further treatment in patients with breast cancer that has responded poorly to neoadjuvant treatment.