Preservation of axillary lymph nodes compared to complete dissection in T1-T2 breast cancer patients presenting 1-2 metastatic sentinel lymph nodes : A multicenter randomized clinical trial. Sinodar One Study
[poster presentato al congresso mondiale San Antonio Breast Cancer Symposium 2019]
Sentinel lymph node (SLN) staging is currently used to avoid complete axillary lymph node dissection (ALND) in breast cancer (BC) patients with negative SLNs without jeopardizing survival or regional control. International guidelines keep recommending ALND in the presence of positive (+) SLNs.
However SLN is the only site of axillary metastasis (MTS) in many cases (60%). Retrospective studies have also shown a low risk of locoregional relapse in patients with SLNs+ not receiving ALND.
This latter finding was recently confirmed in a randomized trial comparing SLN biopsy (SLNB) alone with SLNB followed by ALND in patients with 1-2 SLNs+. However the observation of both similar relapse rate and survival in the 2 arms and the conclusion of a non-inferiority of SLNB compared to ALND require cautiousness because of some study limitations: premature enrollment cessation due to death rate lower than expected, short follow-up (6 years), small tumor size (≤2cm in 70% of cases), frequent presence of only microMTS in SLN (40%), prevalent use of “whole breast” adjuvant radiotherapy (>90%) which irradiates the breast but also the I° axillary level, thereby contributing to the low rate of regional relapse in the SLNB arm due to lymph node sterilization.
Consequently further randomized trials with more precise selection criteria based on homogeneous clinico-pathological features and with longer follow-up are needed to confirm that performing only SLNB does not affect survival or relapse risk in patients with 1-2 SLNs+. Only then the procedure could reasonably be introduced in the clinical management of this patient subgroup, providing them also with a better quality of life due to a reduction of morbidities associated to ALND.