De-escalation of axillary surgery in early breast cancer

With the advent of sentinel lymph node biopsy, surgical methods for accurately staging the axilla in patients with early-stage breast cancer have become progressively less extensive, with formal axillary lymph node dissection confined to a dwindling group of patients. Although details of methods for sentinel lymph node biopsy have yet to be standardised, this technique is now widely practised and accepted as standard of care worldwide. In the past 5 years, attention has focused on minimisation of surgical morbidity by restricting further axillary surgery or considering radiotherapy in patients with a small tumour burden in their sentinel nodes. This change in approach to patients with positive sentinel lymph node biopsies has increased the complexity of axillary management, and any policy of de-escalation and avoidance of morbidity must not compromise patient outcomes. This trend for de-escalation has accompanied a shift in understanding of how any residual tumour burden can be adequately managed without surgical extirpation and reliance on effective adjuvant therapies. Indications for omission of completion axillary lymph node dissection in patients with two or fewer nodes containing macrometastases demand further clarification, together with the roles of preoperative imaging in defining axillary nodal burden, deselection of patients for sentinel lymph node biopsy, and provision of radiotherapy. Downstaging of biopsy-proven node-positive patients with neoadjuvant chemotherapy could safely permit sentinel lymph node biopsy alone when the index node has been successfully retrieved at surgery, while nodal deposits of any size continue to mandate completion axillary lymph node dissection. Developments in molecular imaging technologies and percutaneous biopsy techniques could potentially render sentinel lymph node biopsy redundant in the future.