Sentinel lymph node biopsy after neoadjuvant chemotherapy in patients with node-positive breast cancer: guiding a more selective axillary approach

Purpose The role of sentinel lymph node biopsy (SLNB) in breast cancer patients who undergo neoadjuvant chemotherapy (NAC) remains controversial. This study aims to investigate if axillary lymph node dissection (ALND) could be safely omitted after a negative SLNB in cN1/2 patients who become cN0 after NAC. Methods We retrospectively assessed T1–4, cN1/2 patients who were submitted to NAC between 2010 and 2016. T1–T3 patients who achieved complete axillary clinical response underwent SLNB. Those whose SLNs were negative were not subjected to additional ALND. The oncological outcomes of the patients were analyzed. Results Fifty-nine T1–T3 patients (45.0%) achieved a complete axillary response (cN0), and were selected to undergo SLNB. SLNs were detected in 55 of them (93.2%). Seventeen of those patients (30.9%) had SLN metastases detected and subsequently underwent ALND. In contrast, 38 patients (69.1%) had no nodal metastases detected and were managed without complementary ALND. After a mean follow-up of 55.8 months, only one patient (2.6%) submitted to SLNB without a complementary ALND had axillary recurrence as compared with three patients (3.2%) in the ALND group ( p = 0.71). Distant recurrence occurred more frequently among patients submitted to ALND (92.1%) than among those only submitted to SLNB (7.9%) ( p < 0.0006). Overall survival and disease-free survival were significantly better in patients who were not submitted to ALND. Conclusion SLNB could be successfully used in guiding a more selective axillary approach in cN+ patients that became cN0 after NAC. Omitting ALND in CN0 patients with negative SLNs did not seem to compromise disease control and oncological outcomes.