Determining Whether High Nodal Burden in Early Breast Cancer Patients Can Be Predicted Preoperatively to Avoid Sentinel Lymph Node Biopsy

PURPOSE: The Z0011 trial showed that axillary lymph node dissection (ALND) can be safely avoided in breast cancer patients with low nodal burden (LNB). ALND can be performed in patients with high nodal burden (HNB). We aimed to determine whether HNB in early breast cancer patients can be predicted preoperatively to avoid sentinel lymph node biopsy (SLNB). METHODS: Early invasive breast cancer patients (cT1-2cN0) were retrospectively reviewed. We excluded patients with neoadjuvant chemotherapy and incomplete data. The patients were divided into the following groups based on surgical histology: no positive (N0), LNB, and HNB, defined as 0, 1–2, and ≥ 3 metastatic lymph nodes (LNs), respectively. Of the patients with metastatic nodal disease, only those with ALND were included in the analysis. Clinical, radiological, and histological parameters were evaluated using logistic regression analysis as predictors of HNB versus LNB and N0 combined. RESULTS: Of the 1,298 included patients, 832 (64.1%), 286 (22.0%), and 180 (13.9%) had N0, LNB, and HNB, respectively. Univariate logistic regression analysis revealed that sonographic features of breast tumor size (p < 0.0001), number of abnormal LNs (p < 0.0001), cortical thickness (p = 0.0002), effacement of the fatty hilum (p < 0.0001), and needle biopsy being performed (p < 0.0001) were indicators of HNB. Breast tumor grade (p = 0.0001) and human epidermal growth factor receptor 2 status (p = 0.0262) were also statistically significant. Among these significant features, multivariable stepwise logistic regression showed that the number of abnormal LNs is the sole independent predictor of HNB (p < 0.0001, area under the curve = 0.774). The positive predictive value of HNB in patients with ≥ 4 abnormal LNs was 92.9%. CONCLUSION: The detection of ≥ 4 abnormal LNs on ultrasound can help to identify HNB patients who require upfront ALND and thus avoid SLNB.