[The advantages of preoperative systemic therapy in breast cancer]

Neoadjuvant systemic therapy is administered preoperatively in order to provide a better preparation for surgery by down sizing the tumour. A recent meta-analysis comparing neoadjuvant and adjuvant chemotherapy demonstrated a 17% (95% CI: 15.1-18.1) increase in breast-conserving operations with equal survival rates and maintenance of local control providing adequate surgery was performed. Comparable results have been reported with neoadjuvant hormonal therapy. However, in the case of hormonal therapy the tumour-shrinking effects persisted when treatment was sustained. Research has shown that the sentinel lymph node procedure continues to be reliable after neoadjuvant therapy. Therefore, axillary lymph node dissection is not necessary if the lymph node metastases have disappeared as a result of the neoadjuvant therapy: down staging. However, further research is needed to confirm the safety of this treatment approach. Assessment oftumour sensitivity during neoadjuvant therapy facilitates analysis of the prognostic value of tumour markers. The aim of this translational research is to provide better selection criteria to identify patients in which the systemic treatment will be beneficial.