A pre-surgical decision-support nomogram for predicting nodal pathologic complete response after neoadjuvant therapy in patients with cN1-3 triple-negative breast cancer

Accurate preoperative prediction of nodal pathologic complete response (NpCR) after neoadjuvant chemotherapy (NACT) is essential for the safe implementation of axillary surgical de-escalation in patients with triple-negative breast cancer (TNBC). However, current assessment methods remain limited in identifying which patients with cN1-3 disease are most likely to benefit from this strategy. This study aimed to develop a pre-surgical decision-support nomogram for use after completion of neoadjuvant therapy, integrating dynamic treatment-response markers to quantify the probability of NpCR. A total of 480 patients with initially cN1-3 TNBC were randomly assigned to a training cohort and a validation cohort at a 7:3 ratio. Independent predictors of NpCR were identified using univariate and multivariate logistic regression analyses and incorporated into a nomogram. Model performance was assessed by the area under the receiver operating characteristic (ROC) curve (AUC), calibration plots, and decision curve analysis (DCA). HER2-low status (P = 0.026, OR = 0.541, 95% CI: 0.314–0.931), breast pathologic complete response (BpCR) (P < 0.001, OR = 9.303, 95% CI: 4.866–17.787), and immunotherapy (P = 0.026, OR = 3.004, 95% CI: 1.138–7.929) were identified as independent predictors of NpCR. The nomogram demonstrated good discrimination, with AUCs of 0.758 in the training cohort and 0.752 in the validation cohort, and showed favorable calibration in both cohorts. Sensitivity analysis showed that adding clinical nodal stage did not significantly improve predictive performance (DeLong’s P = 0.272). DCA further confirmed the model’s clinical utility. We developed and validated a nomogram based on BpCR, immunotherapy, and HER2 status to predict NpCR in patients with cN1–3 TNBC. The nomogram is intended as a pre-surgical decision-support model after completion of neoadjuvant therapy. Although dynamic treatment-response markers demonstrated strong predictive value in our cohort, the role of initial nodal burden warrants further evaluation in larger populations with a higher proportion of cN2–3 patients. These findings may help identify candidates for axillary surgical de-escalation.