European Journal of Surgical Oncology, cilt.51, sa.6, 2025 (SCI-Expanded)
Background: More data is needed for those patients with aggressive tumor biology with a high recurrence risk for de-escalating axillary surgery in clinically N+ breast cancer. We, therefore, investigated the outcome in cN+ patients with HER2+ or triple-negative breast cancer who were treated with sentinel lymph node biopsy alone following neoadjuvant systemic treatment. Material and methods: Clinically N+ patients (cT1-4N1-3M0) with HER2+ and triple-negative breast cancer at admission and downstaged to cN0 with neoadjuvant systemic treatment were included in the study. All patients were treated with sentinel node biopsy alone without further axillary dissection but followed by regional nodal irradiation. Results: Of 259 patients, the pathologic complete response rate was 47.1 %. Overall, 171 (66 %) patients had HER2+ and 88 (34 %) had triple-negative cancer. Of 56 ypN+ patients, the lymph node metastases were macrometastases in 24 (42.9 %) patients. After a median follow-up of 46 months, irrespective of ypN status, isolated axillary, locoregional, and distant recurrence rates were 0.8 %, 2.7 %, and 7.7 %, respectively. Recurrence and disease-specific death rates were not different between HER2+ and triple-negative cancer as well as ypN+ and ypN0 patients. Advanced cT stage (cT3-4) was the only significant factor associated with poor disease-free and disease-specific survivals. Conclusion: Irrespective of the final ypN status and tumor subtype, omission of axillary dissection resulted with low axillary recurrence rate in initially cN+ HER2+ and triple-negative breast cancer patients who were downstaged to cN0 with neoadjuvant systemic treatment and did not receive axillary dissection.