Breast Surgery after Primary Systemic Treatment

Primary systemic treatment (PST) is increasingly established in the treatment of early breast cancer. PST can downstage the T- and N-stage and allow less radical surgery to the breast and the axilla. Furthermore, tumour response to PST is a clinically useful surrogate parameter for disease-free and overall survival at least for certain intrinsic subtypes of breast cancer. Complete histopathologic response (pCR) is an established endpoint of clinical trials and allows the accelerated approval of new drugs. PST requires close interdisciplinary cooperation. This relates especially to the preoperative assessment of primary tumour stage, the continuous evaluation of the response to systemic treatment, the definition and localization of the post-PST surgical resection volume and a standardized histopathologic workup that provides adequate information on the response to PST in the breast and the lymph nodes.