What are the outcomes when isolated tumor cells are found in sentinel nodes after neoadjuvant systemic therapy for breast cancer? In this large, multicenter retrospective cohort study, data was collected from 583 patients who had ypN0i+ disease on sentinel lymph node biopsy after neoadjuvant systemic therapy. Of these, 31% had a completion axillary lymph node dissection and 69% did not. Not unexpectedly, patients who had ALND were more likely to have presented adverse features such as cN2+ disease. Among those who had ALND, 30% had additional positive nodes including isolated tumor cells (18%), micrometastases (7%), and macrometastases (5%). At 3 years, there was no statistically significant difference in the rate of any axillary recurrence (1.5% v 3.1%) or isolated axillary recurrence (0.6% v 1.7%) with or without completion ALND. Important to note, most patients (77%) received regional nodal irradiation. | Montagna, J Clin Oncol 2024
