Objective To investigate the value of shear wave elastography (SWE) parameters in early prediction of pathological response to neoadjuvant chemotherapy (NAC) in invasive breast cancer.

Methods A total of 96 patients with invasive breast cancer who received full course NAC treatment were included. Routine two-dimensional ultrasound and SWE were performed in patients before NAC and after the second cycle to obtain change rate of maximum lesion diameter at the end of the second cycle of NAC (ΔD), change rate of maximum elastic value at the end of the second cycle of NAC (ΔE_max) and change rate of average elastic value at the end of secondcycle of NAC(ΔE_mean). All patients were treated surgically and were divided into pathological complete response (PCR) group(n=33) and non-PCR group(n=63) according to Miller&Payne's pathological grade. The clinicopathological data and elastic quantitative parameters of the two groups were compared. Receiver operating characteristic (ROC) curves were plotted to analyze and compare their predictive efficacy.

Results Multivariate Logistic regression analysis showed that human epidermal growth factor receptor 2 (HER2) and ΔE_max were independent predictors of NAC pathological response (OR=6.25, P < 0.05; OR=3.72, P < 0.05). The prediction efficiency of the combined model of HER2 and ΔE_max was optimal, with the area under the curve (AUC) of 0.87 (95%CI, 0.79 to 0.94).

Conclusion The change rates of SWE elastic parameters have predictive value in the early stage of NAC for breast cancer. The combined HER2 and ΔE_max model can improve the diagnostic efficiency in predicting the pathological response of NAC.