Failure of sentinel lymph node mapping in breast cancer patients qualified for treatment sparing axillary lymph nodes-Clinical importance and management strategy-One-center analysis.

Sentinel lymph node biopsy (SLNB) is a standard in diagnostic and therapeutic management of patients with nonadvanced invasive breast cancer. The aim of this paper was to evaluate the clinical importance of the failure of sentinel lymph node (SLN) identification during SLNB performed to spare axillary lymph nodes. A total of 5396 patients with invasive breast cancer qualified for SLNB, treated in a period from Jan 2004 to June 2018. All cases of the failure of SLN identification and reasons underlying this situation were analyzed retrospectively. In 196 (3.6%) patients, SLN was not identified (group I), and this resulted in a simultaneous axillary lymph node dissection. 48.5% patients from this group were diagnosed with cancer metastases to lymph nodes (vs 23.6% patients with SLN removed-group II, P < .00001)-stage pN1 in 44.2% of the cases, stage pN2 in 22.1% of the cases, and pN3 in 33.7% (in group II-73.4%, 19.5% and 7.1%, respectively), with a presence of extracapsular infiltration in 68.4% patients (vs 41.7% in group II) and with a significantly higher percentage of micrometastatic nature in group II (17.0%, vs 3.2% in group I). The failure of intraoperative sentinel lymph node mapping indicates a significantly increased risk of breast cancer metastases to the axillary lymph system. At the same time, it can also indicate higher cancer stage and its increased aggressiveness. For this reason, in such situation performance of axillary lymph node dissection still appears to be the approach most advantageous for patients.