Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

A panel of international breast cancer experts formulated a declaration of consensus regarding many key issues in the use of primary systemic therapy (PST) either in clinical routine or research practice. The attainment of pathological complete response (pCR), defined as no residual invasive tumor in the surgical specimens both in breast and in axillary nodes, is one of the main goals of PST, and pCR can be used as the primary objective in prospective clinical trials. However, pCR is not a reliable endpoint with all treatment approaches, and alternatives such as Ki67 index of the residual invasive disease or after 2 weeks of PST are also potential endpoints. PST has several advantages: breast conservation and the unique opportunity to obtain information on the interaction between treatment and tumor biology. Changes in tumor biology after PST are an early phenomenon; so, an additional core biopsy performed after 14 days from treatment start should be considered in clinical trials.

Original publication




Journal article


J Natl Cancer Inst Monogr

Publication Date





147 - 151


Antineoplastic Agents, Antineoplastic Agents, Hormonal, Antineoplastic Combined Chemotherapy Protocols, Biomarkers, Tumor, Biopsy, Breast Neoplasms, Chemotherapy, Adjuvant, Clinical Trials as Topic, Female, Humans, Ki-67 Antigen, Meta-Analysis as Topic, Neoadjuvant Therapy, Palpation, Receptor, ErbB-2, Remission Induction, Treatment Outcome, Ultrasonography, Mammary