Neoadjuvant Therapy for Breast Cancer: State of the Science and Future Directions

Abstract

Systemic neoadjuvant chemotherapy has long been known to confer clinical benefits for breast cancer patients by downstaging inoperable disease or providing those with operable disease the opportunity for breast conservation, without compromising risk of recurrence. In recent years, its benefits have broadened as it has become a pivotal platform for clinical research, providing new prognostic and predictive insights into in vivo response to therapy and long-term outcomes. The use of neoadjuvant chemotherapy in the research setting has expanded our knowledge of heterogeneity in tumor biology and chemosensitivity and provided insights into the relationships between molecular signatures of tumors, pathologic complete response (pCR), and long-term outcomes. This has provided opportunities to specifically select patients who might benefit from novel therapies and test these in a more efficient manner. Despite these major advancements, however, the majority of patients do not attain a pathologic complete response with systemic neoadjuvant chemotherapy. This review describes the standard of care for systemic neoadjuvant therapy for breast cancer and discusses current management controversies and ongoing clinical trials designed to increase the proportion of patients who currently achieve a pCR.