Performance of Mida??Treatment Breast Ultrasound and Axillary Ultrasound in Predicting Response to Neoadjuvant Chemotherapy by Breast Cancer Subtype

摘要

Background. The primary objective was to determine whether mida??treatment ultrasound measurements of index breast tumors and index axillary nodes of different cancer subtypes associate with residual cancer burden (RCB). Methods. Patients with invasive breast cancer who underwent neoadjuvant chemotherapy and had prea??treatment and mida??treatment breast and axillary ultrasound were included in this singlea??institution, retrospective cohort study. Linear regression analysis assessed associations between RCB with (a) change in index breast tumor size, (b) change in index node size, and (c) absolute number of abnormal nodes at mida??treatment. Multivariate linear regression was used to calculate besta??fit models for RCB. Results. One hundred fiftya??nine patients (68 triple negative breast cancer [TNBC], 45 hormone receptor [HR]+/human epidermal growth factor receptor 2 [HER2]a??, and 46 HRa??/HER2+) were included. Median age at diagnosis was 50 years, range 30a??76. Median tumor size was 3.4 cm, range 0.9a??10.4. Pathological complete response/RCBa??I rates were 36.8% (25/68) for TNBC patients, 24.4% (11/45) for HR+/HER2a?? patients, and 71.7% (33/46) for HRa??/HER2+ patients. Linear regression analyses demonstrated associations between percent change in tumor ultrasound measurements at mida??treatment with RCB index score in TNBC and HR+/HER2a?? (pa??a??.05) but not in HRa??/HER2+ (pa??a??.05) tumors and an association between axillary ultrasound assessment of number of abnormal nodes at mida??treatment with RCB index score across all subtypes (pa??a??.05). Conclusion. Performance characteristics of breast ultrasound associated with RCB vary by cancer subtype, whereas the performance characteristics of axillary ultrasound associated with RCB are consistent across cancer subtype. Breast and axillary ultrasound may be valuable in monitoring response to neoadjuvant therapy. Implications for Practice. The differential performance characteristics of breast ultrasound by molecular subtype and the consistent performance characteristics of axillary ultrasound across molecular subtypes can have clinical utility in monitoring response to neoadjuvant therapy.