Tailored axillary surgery – a novel concept for clinically node positive breast cancer
ypN0, pN1
MAXILLARY TUMOR, RESIDUAL DISEASE, DISEASE, RECRUITMENT
To date, the only way to omit ALND in patients with clinically node-positive is to achieve nodal pCR after NST, as determined by limited axillary surgery, without removing all axillary LN. This strategy shows clear limitations, namely the necessity of NST in a cohort with mainly luminal tumor biology showing low pCR rates [Technically, the obvious axillary tumor burden is selectively reduced by combining the SLN procedure with the removal of palpably suspicious LN, thereby tailoring the extent of axillary surgery to the extent of axillary disease. Palpable disease is currently rarely encountered during the SLN procedure as it is one of its main contraindications. Another difference to the SLN procedure is the optional use of imaging-guided localization of clipped or suspicious nodes (The concept of tailored axillary surgery (TAS) in the TAXIS trial [For patients to be eligible after NST, residual disease has to be re-confirmed in the LN. In the upfront surgery setting, node-positivity has to be confirmed at diagnosis. Patients are randomly assigned after TAS and intraoperative confirmation of removal of the clipped lymph-node to receive either no further axillary surgery and RNI including the axilla, or to completion ALND and RNI without the axilla in the context of breast/chest wall irradiation. The primary endpoint studied in this non-inferiority trial is disease-free survival, with a projected analysis of the primary endpoint in 2029 [Study flowchart of the TAXIS trial, adapted according to Henke et al. [ypN0 - nodal pathologic complete response after neoadjuvant systemic therapy; RT - radiotherapy.The tested hypothesis is, whether adjuvant RNI including a clinically positive axilla that was turned -by using TAS- into a clinically (macroscopically, grossly) negative axilla is non-inferior to ALND in terms of oncological outcomes, with less associated morbidity and increased QoL [Currently, 44 study centers in 6 countries are involved in the study implementation and patient recruitment. Accrual is again as planned, after a transfer of the study sponsor, showing 663 patients randomized by end of January 2023 (Accrual of the TAXIS trial.The feasibility of TAS has recently been confirmed in a pre-planned substudy of 296 patients [In 225 patients with confirmed clinical node positivity, or residual nodal disease after NST, TAS was performed. In the upfront surgery setting, the median number of removed LN was 5 (IQR 3–7), of which a median of 2 LN (IQR 1–4) were positive. After NST a median of 4 LN (IQR 3–5) were removed, with a median of one positive LN (IQR 1–2). Subsequently, 100 patients underwent completion ALND, removing a median of 14 additional LN, whereas in 70% additional positive nodes were removed. The FNR of TAS in patients undergoing subsequent ALND was 1.8%, with a negative predictive value of 95.5% [Interestingly, palpable nodal disease did not lead to higher postoperative pN stages compared to imaging findings in the upfront surgery setting (pN1 in 36.4% vs. 32.4% respectively) [Accrual completion of the TAXIS trial is projected for 2025, with the primary endpoint analysis expected in 2029.