Nomogram prediction model for pathological complete response of metastatic axillary lymph nodes of breast cancer after neoadjuvant chemotherapy

To evaluate the predictive value of a nomogram model combining ultrasound features and clinical indicators for pathological complete response (pCR) of metastatic axillary lymph nodes in breast cancer after neoadjuvant chemotherapy (NACT). A total of 109 women with histologically confirmed breast cancer and axillary lymph node metastasis were retrospectively analyzed. Patients were divided into pCR and non-pCR groups after NACT. A nomogram model was established using univariate and multivariate logistic regression analyses. The predictive performance of the clinical model, ultrasound model, and combined model was compared using the area under the curve (AUC). Molecular subtype, clinical stage, pre-NACT metastatic axillary lymph node subtype, post-NACT reduction rate of lymph node short diameter, and post-NACT reduction rate of primary tumor maximum diameter were independent predictors of axillary lymph node pCR. The combined model (AUC 0.844, 95%CI: 0.773–0.915, P < 0.05) showed significantly improved predictive ability compared with the clinical model (AUC 0.725, 95%CI: 0.628–0.823, P < 0.05) and ultrasound model (AUC 0.754, 95%CI: 0.665–0.844, P < 0.05). The nomogram combining ultrasound and clinical indicators effectively predicts pCR of metastatic axillary lymph nodes after NACT and provides a reference for surgical selection. However, the single‑center design, small sample size, and lack of external and prospective validation limit its generalizability. Multi‑center prospective validation is warranted. Axillary lymph node status determines the clinical stage and treatment plan of breast cancer. Clinical features and ultrasound imaging features can be used to predict axillary lymph node status after NACT. The nomogram prediction model shows better predictive performance than the clinical model and ultrasound model alone. The nomogram prediction model can provide evidence for axillary treatment de-escalation after NACT and help clinicians more appropriately evaluate the risks and benefits of sentinel lymph node biopsy (SLNB) after NACT.