Dobruch-Sobczak K, et al. - In this prospective ultrasound (US) analysis, researchers assessed the US response in patients with breast cancer (BC) while undergoing neoadjuvant chemotherapy (NAC). This investigation was performed on 19 malignant tumors before NAC treatment and 7 days following each first four courses of NAC in 13 patients. A statistically significant relationship was found between breast tumors' echogenicity in US, neoplasm size, and stiffness and NAC response. The change in tumor echogenicity could especially foresee a pathological response with reasonable accuracy and can be considered in NAC monitoring. Important factors in predicting response to NAC were lesion size and elasticity.