Impact of using intraoperative nomograms with one-step nucleic acid amplification to omit axillary lymph node dissection in patients with breast cancer who underwent mastectomy

BACKGROUND: Omission of axillary lymph node dissection (ALND) in patients with positive sentinel lymph nodes (SLN) who underwent mastectomy remains controversial. In this study, we reported the omission of ALND in mastectomy cases with positive SLNs, using a nomogram to predict non-SLN metastasis. Furthermore, we reported the management of patients with more than four metastatic axillary lymph nodes (ALN). METHODS: We prospectively identified 392 patients with primary invasive breast cancer (cT1-3, N0) who underwent a mastectomy and were diagnosed with SLN metastasis using one-step nucleic acid amplification (OSNA). We used our predictive nomogram, including the OSNA factor for patients with positive SLNs, to make decisions regarding ALND and determine the probability of four or more axillary lymph node metastases. RESULTS: Of the 392 patients, 124 (31.3%) had one or two metastases to the SLNs, and 31 (25.0%) had a predictive probability of a nomogram for metastasis to non-SLNs (