Neoadjuvant systemic treatment of breast cancer.

Neoadjuvant systemic breast cancer therapy is the administration of systemic therapy to eligible breast cancer patients prior to surgery. This treatment modality was developed out of necessity to downstage inoperable tumors, but it has evolved into a tool for breast conservation surgery. The neoadjuvant approach is also commonly used now to explore the efficacy of new therapeutics by assessing their impact on pathologic complete response or other endpoints. This article will review the foundations of this treatment modality and the latest progress in the field. Considering the heterogeneity of breast cancer, it is clear that no single treatment will fit all types of breast cancer. Thus, there is a need to understand the biological underpinnings of the different types of breast cancer in order to design better treatments that will ultimately improve the eradication rate of this disease.