Prof. dr. Thorsten Kühn, Díe Filderklinik

🎤 Axilla around NAC
Neoadjuvant chemotherapy improves outcomes in some subsets of patients and reduces the extent of surgical interventions. Axillary surgery after NACT is a diagnostic procedure in clinically node-negative patients (ycN0) irrespective of the cN-status at presentation. For patients with initially uninvolved lymph nodes (cN0), SLNB is the standard of care, while for patients with biopsy-proven lymph node involvement (cN+), marking the lymph node metastasis improves the identification and accuracy of surgical staging if converted to ycN0. In cN0 patients with TN or HER2-positive disease and an excellent response in the breast (pCR), axillary lymph node involvement is rare (< 2 %). Omission of axillary staging is discussed in this subgroup and addressed in clinical trials. In patients with low-volume SLN/TAD/MARI involvement (ypN0(i+) and ypN1(mi)), completion ALND reveals a two-fold higher rate of additional lymph node involvement compared to primary surgery, and an upgrade of the ypN-stage in 6% and 11%, respectively. This diagnostic information, however, does not translate into a modification of systemic or regional treatment decisions, so that cALND has no benefit when performed for diagnostic purposes in low-volume SLN/TLN involvement. In the absence of randomised data from the ALLIANCE 11202 trial, ALND remains a standard of care for ycN0ypN1 patients, while large retrospective studies suggest radiotherapy is non-inferior. In patients with clinically positive lymph nodes after NACT (ycN+), the routine use of ALND should be questioned, given the high false-positive rate of clinical findings after NACT, including all imaging modalities.

🎤What did we learn from AXSANA?
The AXSANA (AXillary Surgery After NeoAdjuvant chemotherapy) / EUBREAST 3 study was initiated in 2019 as an initiative of the EUBREAST study group to assess different surgical strategies for the axillary management of patients treated with neoadjuvant chemotherapy and converted from a positive to a negative lymph node status. 388 study sites from 26 countries recruited 7.300 patients since June 2020. The endpoints of the study are axillary recurrence-free survival, invasive breast cancer-specific survival, quality of life, and health economics. Important insights from published or submitted data show:

1. Nodal pCR rates increased by around 20% for all intrinsic subtypes over the last 2 decades (compared to preexisting metaanalyses)
2. Clinical (palpation) and all imaging procedures (US/MRI/PET are unreliable after NACT (sensitivity/specificity, negative and positive predictive value) even in combination
3. SLNB/TLNB/TAD are not inferior to ALD irrespective of tumor biology and initial tumor burden at 3 years
4. Regional recurrences reflect systemic but not surgical treatment failure
5. Initial nodal burden does not impact regional recurrences
6. Probe-guided procedures provide significantly higher detection rates for the TLN compared to clip localisation
7. Diagnostic ALND after low volume SLN/TLN involvement does not provide clinically significant informations
8. SLNB/TAD are associated with less functional impairment compared to ALND

💬 Biography
Prof. Kuehn is a German Breast Surgeon. He is head of the Interdisciplinary Breast Center of the Filderklinik, Germany, and Senior Consultant at the University of Ulm, Germany. He is chairman of the European Breast Cancer Research Association of Surgical Trialists (EUBREAST e.V.) and a member of the German Guideline Committee for Breast Cancer for over 15 years. He was the Principal Investigator of the SENTINA trial and is head of the ongoing international multicenter AXSANA trial. Prof. Kuehn dedicated his scientific career to de-escalating strategies in the surgical treatment of breast cancer. He published more than 250 papers in peer-reviewed journals