Diagnostic accuracy of sentinel lymph node biopsy after neoadjuvant chemotherapy in breast cancer patients: A single-institutional experience.

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Background: Sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NACT) is a critical tool for axillary staging in breast cancer. Performance of SLNB after NACT has been an area of interest of late and is still evolving. This study evaluates the feasibility, outcomes, and diagnostic accuracy of SLNB after NACT at our institution. Methods: We analysed 38 female patients with non-metastatic breast cancer who received NACT followed by surgery. All patients underwent dedicated axillary ultrasound +/- fine-needle aspiration cytology (FNAC) prior to NACT.All patients with positive node underwent marking of the most suspicious node to help in Targeted Axillary Dissection (TAD), post chemotherapy. The diagnostic accuracy of SLNB was determined by comparing SLNB results with completion axillary dissection in node positive patients. Results: The mean patient age was 57.8 years. The cohort included 35.7% triple-negative (TNBC), 28.6% hormone receptor-positive (HR+), and 25.0% HER2-positive tumours with 31 patients having cT2 disease. Ten patients had upfront nodal involvement confirmed with FNAC (all were cN1) with nodal clipping done prior to chemotherapy Following NACT, all 38 patients underwent SLNB, with a 100% identification rate and mean of 3 nodes per patient. Among patients with FNAC positive nodes, the TAD node and SLNB node were the same in all 10 patients. Only 5 patients had positive SLNB .Among the 10 patients with positive nodal FNAC, 5 had complete pathological response in SLNB as well as rest of axillary dissection, while 3 had only SLNB being positive and 2 had positive nodes in the rest of the axilla also. A pathological complete response (pCR; ypT0N0) was achieved in 50% of patients SLNB detected all patients who had axillary disease, even in node positive patients with false negative rate of zero. Conclusions: In our experience, SLNB after NACT is a feasible and accurate procedure for axillary staging. These findings support using SLNB to de-escalate axillary surgery in patients who respond well to NACT, minimising morbidity without compromising oncologic safety.

Demography and performance of SLNB post NACT.