International expert consensus on primary systemic therapy in the management of early breast cancer: Highlights of the Fifth Symposium on Primary Systemic Therapy in the Management of Operable Breast Cancer, Cremona, Italy (2013)

Expert consensus-based recommendations regarding key issues in the use of primary (or neoadjuvant) systemic treatment (PST) in patients with early breast cancer are a valuable resource for practising oncologists. PST remains a valuable therapeutic approach for the assessment of biological antitumor activity and clinical efficacy of new treatments in clinical trials. Neoadjuvant trials provide endpoints, such as pathological complete response (pCR) to treatment, that potentially translate into meaningful improvements in overall survival and disease-free survival. Neoadjuvant trials need fewer patients and are less expensive than adjuvant trial, and the endpoint of pCR is achieved in months, rather than years. For these reasons, the neoadjuvant setting is ideal for testing emerging targeted therapies in early breast cancer. Although pCR is an early clinical endpoint, its role as a surrogate for long-term outcomes is the key issue. New and better predictors of treatment efficacy are needed to improve treatment and outcomes. After PST, accurate management of post-treatment residual disease is mandatory. The surgery of the sentinel lymph-node could be an acceptable option to spare the axillary dissection in case of clinical negativity (N0) of the axilla at the diagnosis and/or after PST. No data exists yet to support the modulation of the extent of locoregional radiation therapy on the basis of the response attained after PST although trials are underway.