A prospective study found that sentinel lymph node biopsy may be an accurate method of axillary staging in selected patients with locally advanced breast cancer who achieve a clinical nodal response to neoadjuvant chemotherapy—potentially allowing some patients to avoid axillary lymph node dissection. The findings, which were reported by Barrio et al in the Journal of Clinical Oncology, demonstrated a false-negative rate of 2.1% among patients with adequate sentinel lymph node mapping and residual nodal disease.
Study Details
The investigators conducted a prospective, single-arm study at Memorial Sloan Kettering Cancer Center and Miami Cancer Institute to assess the feasibility and accuracy of sentinel lymph node biopsy following neoadjuvant chemotherapy. Eligible adults had locally advanced breast cancer, defined as clinical T4 disease, including inflammatory breast cancer, and/or clinical N2/N3 nodal involvement. Patients were required to have no clinically suspicious palpable axillary nodes following chemotherapy.
Between August 2017 and December 2025, 456 patients were screened, of whom 369 (81%) became clinically node-negative after chemotherapy. The final evaluable cohort included 145 patients: 44% with inflammatory breast cancer, 23% with other clinical T4 disease, 12% with clinical N2 disease, and 21% with clinical N3 disease. The median age was 49 years (interquartile range = 42–59 years); 39% had HER2-positive disease, and 28% had triple-negative breast cancer.
All patients underwent sentinel lymph node biopsy using dual-tracer mapping, followed by axillary lymph node dissection to assess residual disease. The primary endpoint was the false-negative rate among patients with adequate mapping.
Key Results
At least one sentinel lymph node was identified in 108 patients (74%), whereas mapping failed in 37 patients (26%). Three or more sentinel nodes were retrieved in 82 patients (57%), and an additional 5 patients had adequate mapping through retrieval of one or two sentinel nodes that included the clipped node. Overall, 87 patients (60%) met the criteria for adequate mapping.
Among these 87 patients, the nodal pathologic complete response rate was 46%, and 47 patients (54%) had residual nodal disease. Only one false-negative sentinel node biopsy occurred, yielding a false-negative rate of 2.1% (95% confidence interval [CI] = 0.1%–12.7%). Across all 108 patients with successful mapping, the false-negative rate was 5.4% (95% CI = 1.4%–15.8%). However, among patients with only one or two sentinel nodes retrieved without a clipped node, the false-negative rate increased to 22.2% (95% CI = 3.9%–59.8%).
Sentinel node identification rates were 67% in patients with inflammatory breast cancer, 73% in those with other clinical T4 disease, 83% in those with clinical N2 disease, and 87% in those with clinical N3 disease (P = .2). Among patients with inflammatory breast cancer and adequate mapping, the false-negative rate was 5%.
The investigators concluded: “In a prospective cohort of patients with [locally advanced breast cancer], the [sentinel lymph node] identification rate was 74% and the [false-negative rate] was 2.1%, suggesting that [sentinel lymph node biopsy] may be an appropriate method to stage the axilla in [locally advanced breast cancer] after downstaging with [neoadjuvant chemotherapy].”
Andrea V. Barrio, MD, of Breast Service, Department of Surgery, Memorial Sloan Kettering Cancer Center, New York, is the corresponding author for the Journal of Clinical Oncology article.
DISCLOSURE: The study was supported by NIH/NCI Cancer Center and others. For full disclosures of the study authors, visit ascopubs.org.
