Application of Sound/Insema at a Metropolitan Breast Cancer Program: Who Needs a Sentinel Node Biopsy?

Document Type

Conference Proceeding

Publication Date

2-20-2026

Publication Title

Ann Surg Oncol

Keywords

abemaciclib, ribociclib, adult, aged, breast cancer, cancer staging, clinical article, conference abstract, controlled study, diagnosis, female, histology, human, human tissue, major clinical study, micrometastasis, sentinel lymph node biopsy, surgery

Abstract

In an era of de-escalation, omitting sentinel lymph node biopsy (SLNB) in patients with a negative axillary ultrasound (SOUND/ INSEMA) has become a priority focus. Inclusion criteria between the two trials have variability in T-stage, high risk features, and definition of "suspicious node." We aimed to define the false negative rate (FNR) of negative axillary ultrasound performed at our institution and determine if there are any tumor or patient characteristics that may increase the risk of a false negative ultrasound to further delineate patients who are appropriate for SLN biopsy omission. METHODS: Our institutional IRB approved prospective breast cancer database was queried for cases undergoing axillary ultrasound followed by SLN biopsy from October 2023 to August 2025. Patient demographics, clinical characteristics, tumor biology, ultrasound findings, core biopsy pathology (tumor and node if applicable), interpreting radiologist, adjuvant treatment offered/ provided and clinical/surgical pathologic staging were recorded. RESULTS: We identified 225 internally performed axillary ultrasounds. Of these, 154 were called negative (68.4%) with 131 cases revealing negative SLNB and 23 with a positive SLN -17 macrometastases (FNR 10.3%) and 6 micrometastases (FNR 4.2%). Of the 17 cases with macrometastases, 13 had 1 positive SLN and 4 had 2 positive SLNs. No cases had >3 positive SLN. Of the 73 axillary ultrasounds called suspicious, 4 had a positive SLNB (TPR 2.7%). There was a statistically significant association between histology and false negative ultrasound-ILC was seen in a higher proportion of false negative ultrasound cases (p=0.022). The SLNB findings resulted in recommendations for changes in the adjuvant therapy plan in 5 patients: Ribociclib in 2 patients, Ribociclib and Verzenio in 1 patient, PMRT in 2 patients. CONCLUSIONS: Our institutional axillary ultrasound macrometastasis FNR (10.3%) falls within the SOUND FNR (8.7%) and INSEMA FNR (11.6%) which is similar to published SLNB FNR (10%). We found that ILC histology was significantly associated with a false negative ultrasound in our limited dataset. We will continue to follow SOUND/INSEMA criteria for SLNB deferral given these results. Further investigation is needed into predicting the possibility of false negative axillary ultrasound as well as identifying strategies to minimize the FNR.

Volume

33

Issue

1

First Page

S20

Last Page

S21

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