Study of changes in tumor blood flow for the assessment of early response to neoadjuvant chemotherapy in breast cancer patients

Background. Over the past 20 years, there has been a change in approaches to the treatment of breast cancer, in particular, a significant increase in the role of drug therapy. Breast cancer response to neoadjuvant chemotherapy is currently considered as a surrogate biomarker, which allows evaluation of the clinical course and prognosis of the disease. To solve this problem, it is necessary to assess the functional and metabolic changes in tumor tissue during treatment. Doppler ultrasound is a non-invasive, affordable, and low-cost imaging technique that can be safely used for repeated measurements. The purpose of the study was to study vascular changes in the tumor by power Doppler ultrasound for the evaluation of the early breast cancer response to neoadjuvant chemotherapy. Material and Methods. From May 2017 to August 2019, 63 patients with breast cancer received neoadjuvant chemotherapy. Changes in the tumor blood flow were assessed before starting the treatment and prior to the second course of neoadjuvant chemotherapy using Doppler scanning. Changes in tumor blood floor after chemotherapy were compared with the pathological tumor response after surgical treatment. Results. in the vast majority of cases (78 %), there was a decrease in the number of tumor vessels after the first cycle of neoadjuvant chemotherapy independent of the grade of pathological response. in 8 cases with increased vascularization after the first cycle of neoadjuvant chemotherapy, histological examination of the removed tumor showed no response / weak response to treatment in the absence of peritumoral inflammation. in 5 cases, a sharp increase in the number of vessels around large areas of intranodular necrosis and peritumoral inflammation was observed. in general, a comparison of changes in tumor vascularization and pathological response revealed a weak, although statistically significant, negative correlation between changes in the tumor blood flow after neoadjuvant chemotherapy and pathological response. Conclusion. it was not possible to establish an unambiguous relationship between the reaction of the vascular bed and the tumor response to the cytostatic effect. An increase in the number of tumor vessels in the absence of peritumoral inflammation was the only situation when changes in tumor blood flow during chemotherapy can be unambiguously interpreted as a predictive criterion for the absence / weak response of the tumor to treatment.