Retrospective study of nodal burden and oncologic outcomes in patients with residual isolated tumor cells after neoadjuvant chemotherapy

The nodal burden of patients with residual isolated tumor cells (ITCs) in the sentinel lymph nodes (SLNs) after neoadjuvant chemotherapy (NAC) (ypN0i+) is unknown, and axillary management is not standardized. The retrospective OPBC-05/ICARO study, at 62 centers in 18 countries, included 583 patients, of whom 182 (31%) had completion axillary lymph node dissection (ALND) and 4-1 (69%) did not. The mean number of SLNs with ITCs was 1.2. Additional positive nodes were found at ALND in 30% of patients, but only 5% had macrometastases. The 3-year rates of any axillary and any invasive recurrence were 2% (95% CI 0.95-3.6) and 11% (8-14), respectively, with no statistical difference by type of axillary surgery. The authors conclude that the nodal burden in patients with ypN0(i+) was low, and axillary recurrence after ALND omission was rare. These results do not support routine ALND in all patients with ypN0(i+).