Breast ultrasonography in the measurement of residual tumor after neoadjuvant chemotherapy

Introduction: The role of primary chemotherapy in breast cancer is well established and has positively impacted the number of conservative surgeries. However, for effective locoregional control, it is necessary for complete resection of the residual tumor, with histopathological free margins. Preoperative evaluation of the residual tumor is essential. A clinical examination is impaired due to tissue alterations induced by chemotherapy, and the use of imaging methods had conflicting results. Objective: The aim of this study was to evaluate the agreement between the ultrasound measurement and the histopathological measurement of the residual tumor in breast cancer patients undergoing neoadjuvant chemotherapy. Methods: A cross-sectional study was conducted comparing the average and other measures of dispersion of the echographic and histopathological measurements of the residual tumor. Additionally, we compared the average and other measures of dispersion of the individual differences between the echographic and histopathological measurements of the residual tumor. The scenario was a quaternary hospital in Rio de Janeiro where breast cancer patients were treated. Results: The average ultrasound measurement was 18 mm (95%CI 13.75–22.25), with a median of 16. The average histopathological measurement was 16 mm (95%CI 11.62–20.38), with a median of 12. The average of the individual differences between the echographic and histopathological measurements of the residual tumor was 2 mm (95%CI 0.38–4.38), with a median of 2 mm. Conclusion: Ultrasonography is an effective tool in the preoperative evaluation of breast cancer patients undergoing primary chemotherapy.