A nomogram integrating ultrasound features of the primary tumor and axillary lymph nodes with clinicopathological factors to predict high axillary lymph node burden in invasive breast cancer

Objective To develop and validate a nomogram that integrates ultrasound features of the primary tumor and axillary lymph nodes with lymphovascular invasion (LVI) for early postoperative risk stratification of high axillary nodal burden (HNB; ≥3 positive nodes) in patients with node-positive invasive breast cancer. Methods A total of 175 consecutive patients with node-positive invasive breast cancer who underwent surgery between July 2023, and October 2025 were retrospectively included in the development cohort, and an additional 86 patients treated during the same period comprised of the internal validation cohort. Two senior radiologists independently reviewed preoperative ultrasound images and clinicopathological data, including LVI assessed in postoperative surgical specimens. Univariate and multivariate logistic regression analyses were performed to identify independent predictors and construct the nomogram. Results The proportions of patients with posterior echo attenuation, microcalcification, claw sign, angular margin sign, spiculation sign (significant long spicules/short spicules), suspicious axillary lymph node status, and lymphovascular invasion were all higher in the high-load group than in the low-load group (all P < 0.05). Multivariate regression analysis showed that the absence of the marginal angular margin sign ( OR = 0.190, 95% CI : 0.084 - 0.432, P < 0.001) and the normal axillary lymph node status ( OR = 0.208, 95% CI : 0.089 - 0.456, P < 0.001) were independent protective factors for HNB, whereas lymphovascular invasion (presence) ( OR = 2.707, 95% CI : 1.363 - 5.377, P = 0.004) was an independent risk factor. ROC analysis showed that the combined detection of marginal angular margin sign, lymph node status, and lymphovascular invasion had a higher AUC value for predicting HNB than individual detections ( Z = 4.176, 3.781, and 3.672, respectively; P < 0.05). Conclusion The nomogram incorporating the angular margin sign, axillary lymph node ultrasound status, and LVI provides effective early postoperative risk stratification for HNB in patients with node-positive invasive breast cancer and may facilitate timely adjuvant treatment decision-making.