Adjuvant and neoadjuvant therapy for breast cancer.

Systemic therapies for operable breast cancer patients have improved outcomes and have thus become standard treatments. Recently, new molecular target drugs and regimens are being developed based on the predicted sensitivity for specific breast cancer histological types. Systemic therapy is selected according to recurrence risk, with the treatment for low-risk patients being de-escalated, while high-risk patients receive aggressive systemic treatment with an adequate dose and duration. Neoadjuvant systemic therapy has a different aim. The efficacy of systemic therapies, based on the sensitivities to drugs, is supported by improvements in the rate of breast-conserving therapy. The response to neoadjuvant systemic therapy is the most important factor for predicting outcomes and selecting the optimal adjuvant therapy. Novel biological markers unique to individual patients allow appropriate targeted therapy, which can achieve optimal efficacy.