Objective:To analyze the correlations between the ultrasound contrast features and the expression of human epidermal growth factor receptor 2(HER-2)of molecular biological indicators of breast cancer,and between ultrasound elastography features and that.Methods:A total of 63 patients with invasive breast cancer who admitted to The Affiliated Suzhou Hospital of Nanjing Medical University and The First Affiliated Hospital of Jiamusi University from February 2019 to June 2022 were selected as the study subjects.The HER-2 positive expression of molecular biological indicator of breast cancer was measured by immunohistochemistry.According to the immunohistochemical results,the patients were divided into positive group(22 cases)and negative group(41 cases).All patients underwent examinations of ultrasound contrast and ultrasound elastography.The differences of the features of ultrasound contrast and ultrasound elastography between the two groups were analyzed and compared.The influencing factors of HER-2 positive expression were analyzed by binary logistic regression,and the receiver operating curve(ROC)was established to assess respectively the values of single ultrasound contrast,single ultrasound elastography and the combination of them in predicting HER-2 positive expression.Results:There was significant differences in the features of ultrasound elastography between the two groups.The ratios of the irregular shape and burr at the edge of the imaging features of the patients with HER-2 positive expression were significantly higher than those of the patients with HER-2 negative expression[(86.4%vs.58.5%)and(77.3%vs.51.2%)],and the differences were statistically significant(x2=5.117,4.060,P<0.05),respectively.The difference of the features of ultrasound contrast between two groups was significant.The ratios of nourishing vessels,and the lesion enlargement≥3 cm after angiography in patients with HER-2 positive expression were significantly higher than those in the patients with HER-2 negative expression[(77.3%vs.41.5%)and(81.8%vs.39.0%)],the differences were statistically significant(x2=7.390,10.554,P<0.05),respectively.The features(shape,edge,nourishing vessels and lesion enlargement after contrast)of ultrasound contrast and ultrasound elastography were used respectively as independent variables,and the HER-2 positive expression was used as dependent variables.The logistic regression analysis showed that regular shape,smooth edge,without nourishing vessels and enlarged lesion<3 cm after angiography were protective factors for HER-2 positive expression of patients with breast cancer(OR=0.185,0.199,0.070,0.186,P<0.05),respectively.The areas under curve(AUC)values of the ROC curve of imaging features(shape,edge,nourishing vessels,and lesion enlargement after angiography)of ultrasound contrast and ultrasound elastography were respectively 0.630,0.639,0.679 and 0.714 in single predicting HER-2 positive expression of patients with breast cancer,and that of the combination of them was 0.874 in prediction.Conclusion:In features of ultrasound contrast and ultrasound elastography,the shape,edge,nourishing vessels and the enlargement lesion after contrast were the influencing factors of HER-2 positive expression in patients with breast cancer.The combined assessment of ultrasound contrast and ultrasound elastography before surgery has certain clinical reference value in predicting HER-2 expression.