Axillary surgery after neoadjuvant therapy in initially node-positive breast cancer: international EUBREAST survey.

Background: There is no consensus on axillary management after neoadjuvant therapy (NAT) in patients with clinically node-positive (cN+) breast cancer. To investigate current clinical practice, an international survey was conducted among breast surgeons and radiation oncologists. The aim of the first part of the survey was to provide a snapshot of international discrepancies regarding axillary surgery in this context.

Methods: The European Breast Cancer Research Association of Surgical Trialists (EUBREAST) developed a web-based survey containing 39 questions describing clinical scenarios in the setting of axillary management in patients with cN1 disease converting to ycN0 after NAT. The survey was then distributed to breast surgeons and radiation oncologists via 14 breast cancer societies between April and October 2021.

Results: Responses from 349 physicians in 45 countries were recorded. The most common post-NAT axillary surgery in patients with cN1 disease converting to ycN0 was targeted axillary dissection (54.2 per cent), followed by sentinel lymph node biopsy (SLNB) alone (20.9 per cent), level 1-2 axillary lymph node dissection (ALND) (18.4 per cent), level 1-3 ALND (4 per cent), and targeted lymph node biopsy (2.5 per cent). For SLNB alone, dual tracers were most commonly used (62.3 per cent). Management varied widely in patients with ambiguous axillary status before initiation of treatment or a residual metastatic burden in the axilla after NAT. In patients with ycN+ tumours, ALND was the preferred surgical approach for 66.8 per cent of respondents.

Conclusion: These results highlight the wide heterogeneity in surgical approaches to the axilla after NAT. To standardize the guidelines, further data from clinical research are urgently needed, which underlines the importance of the ongoing AXSANA (EUBREAST-3) study.