Abstract:Objective: Combined ultrasound and axillary metastatic clipped lymph nodes to develop a model to predict axillary pathological complete response after neoadjuvant systemic therapy in breast cancer patients with clinically lymph node-positive. Methods: The subjects were breast cancer patients who were admitted to the Nanjing Medical University First Hospital and planned to receive neoadjuvant systemic therapy. The most suspicious lymph node with biopsy-confirmed metastasis was selected and a clip was inserted under ultrasonography guidance before neoadjuvant systemic therapy. In total, 88 patients were randomly assigned to the testing or validation set at a ratio of 7:3. Univariate and multivariate logistic regression analyses of the testing set were performed. A risk score model was developed based on the results of multivariate analysis. Results: The axillary pathologic complete response rate was 48% (42/88). Hormone receptor status, N grade by ultrasonography before neoadjuvant systemic therapy, change in the number of abnormal LNs as determined by ultrasonography, and change in cortical thickness of the clipped LN were identified as independent factors and used to develop a risk score model. At scores of ?13 to ?9 and 1 to 10, the axillary pathologic complete response rate of the testing set was 100% and 0%, respectively. The area under the receiver operating characteristic curve of the testing and validation sets was 0.931 (95% confidence interval [CI] = 0.868–0.994) and 0.762 (95% CI = 0.576–0.947), respectively. Conclusion: The risk score model based on ultrasound and clipped lymph node accurately predicted the axillary lymph node status of breast cancer patients with clinical lymph node positive after neoadjuvant systemic therapy. The false-negative rate of residual axillary LN metastasis was 0% in patients with risk scores of ?13 to ?9. Hence, ALND can be excluded for these patients.