Is the Clipped Node Enough? Successful Retrieval and False Negative Rate of the Clipped Node After Neoadjuvant Chemotherapy.

Abstract

Various techniques exist to decrease the false negative rate (FNR) of axillary surgical staging post neoadjuvant chemotherapy (NAC). While biopsy-proven positive lymph nodes (LNs) are often clipped prior to NAC, the value of clipped node localization is debated. We identified cT0-4c biopsy-proven cN+ breast cancer patients with a clipped LN treated with NAC and definitive surgery (September 2016-July 2024). The axillary staging procedure included sentinel lymph node (SLN) surgery or targeted axillary dissection (TAD). Frequency of the clipped node being an SLN and FNR of the clipped node versus all nodes removed during SLN surgery/TAD were determined. Of 540 patients with 541 cN+ breasts with cancer, 456 patients had a positive LN clipped prior to NAC and underwent axillary surgical staging (404 TAD, 52 SLN surgery). The clipped node was retrieved in 93% of eligible patients (96% TAD vs. 77% SLN surgery; p < 0.001) and, if retrieved, was an SLN in 86% (85% TAD vs. 92.5% SLN surgery; p = 0.20). The median number of nodes retrieved was four for both SLN surgery and TAD. Among 204 patients with ypN+ disease who had the clipped node and additional non-clipped nodes removed, FNR of the clipped node was 5.4%, and FNR of the SLNs was 4.9%. In a contemporary NAC cohort of cN+ patients, the clipped node was retrieved and was a SLN in most cases. When compared with all nodes removed during SLN surgery/TAD, the clipped node FNR was low, thus supporting the potential for limitation of axillary staging surgery to selective removal of the clipped node alone.