Prediction of tumor shrinkage patterns to neoadjuvant chemotherapy based on pretreatment contrast-enhanced ultrasound and clinical features in breast cancer

Accurate assessment of tumor shrinkage patterns (TSP) following neoadjuvant chemotherapy (NAC) is crucial for determining eligibility for breast-conserving surgery (BCS). In this study, our goal was to evaluate the early predictive value of pretreatment contrast-enhanced ultrasound (CEUS) combined with clinical features for TSP in breast cancer patients following NAC. This study retrospectively included breast cancer patients who underwent NAC followed by surgery between June 2018 and May 2023 at our hospital. According to the postoperative pathology, the patients were divided into concentric shrinkage group and the non-concentric shrinkage group. The CEUS qualitative and quantitative parameters of the lesions before NAC and the clinical features were collected for model construction. The independent predictors of TSP after NAC were determined through univariable and multivariate logistic regression, and a nomogram for predicting concentric shrinkage was established. A total of 64 patients were enrolled in this study. After 6–8 cycles of NAC, 38 patients (59.4%) achieved the concentric shrinkage pattern, while 26 patients (40.6%) did not. The result of multivariate logistic regression analysis demonstrated that progesterone receptor ( PR ), human epidermal growth factor receptor 2 ( HER2 ), time to peak (TTP) and penetrating vessels were independent predictors of TSP ( P < 0.05). Based on the above features, a nomogram was constructed to predict the concentric shrinkage pattern of NAC in breast cancer patients. The area under the receiver operating characteristic curve (AUC) of the nomogram was 0.910 (95% confidence interval: 0.835–0.984), with a sensitivity of 81.6% and specificity of 88.5%. Pretreatment CEUS combined with clinical features demonstrates high early predictive value for TSP following NAC in breast cancer patients. It may assist clinicians in treatment planning and in evaluating the feasibility of BCS following effective chemotherapy.