Introduction: In breast cancer patients with initially metastatic axillary lymph nodes (pN+, ALNs), neoadjuvant systemic treatment (NST) significantly downstages axillary disease. Sentinel lymph node biopsy (SLNB) in well-responded patients has been associated with high false-negative rates (FNR) when less than three nodes are retrieved and a single tracer is used. Targeted axillary dissection (TAD) after node clipping has been proposed to reduce FNR but is costly, labor-intensive, and requires specialized equipment. However, there is limited evidence linking high FNR with worse long-term oncological outcomes, such as recurrence rates. This study evaluates axillary recurrence rates in breast cancer patients downstaged by NST and assessed with SLNB using blue dye alone. Methods: We retrospectively analyzed clinical, pathological, and follow-up data from 245 breast cancer patients treated between 2010 and 2021 across six centers in Turkiye. All patients had pN+, ALNs at diagnosis and were downstaged to ypN0 or ypN0i+ by SLNB with blue dye after NST. Recurrence rates in the breast, axilla, other regional lymphatics, distant organs, and mortality were recorded. Results: Of the 245 patients, 10% had cN2 disease, and 35% had less than three sentinel lymph nodes retrieved. After SLNB, 6% had isolated tumor cells in their nodes, while the rest achieved a pathologic complete response. The median follow-up was 51 months. Only 2% developed ipsilateral axillary recurrence (0.8% isolated), and 18% had any recurrence, primarily as distant metastasis. The mortality rate was 9%. Conclusion: Our study demonstrates that performing SLNB after NST using only blue dye may be a viable and acceptable approach in clinical practice. The oncological safety and adequacy of this simple method should be confirmed with further studies.
Aktaş et al. (Thu,) studied this question.