A prospective cohort study identifying radiologic and tumor related factors of importance for breast conserving surgery after neoadjuvant chemotherapy

• Published in: European journal of surgical oncology Vol. 49; no. 7; pp. 1189 - 1195
• Main Authors: Gulis, K., Ellbrant, J., Svensjö, T., Skarping, I., Vallon-Christersson, J., Loman, N., Bendahl, P.O., Rydén, L.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.2023
• Subjects: Breast cancer; Breast conserving surgery; Breast density; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - drug therapy; Breast Neoplasms - genetics; Cancer and Oncology; Cancer och onkologi; Clinical Medicine; Female; Humans; Klinisk medicin; Mastectomy; Mastectomy, Segmental; Medical and Health Sciences; Medicin och hälsovetenskap; Molecular subtypes; Neoadjuvant Therapy; Neoadjuvant treatment; Neoplasm Staging; Prospective Studies; Breast conserving surgery; Molecular subtypes; Breast density; Breast cancer; Neoadjuvant treatment
• ISSN: 0748-7983; 1532-2157
• DOI: 10.1016/j.ejso.2023.03.225

Neoadjuvant chemotherapy (NAC) is an established treatment option for early breast cancer, potentially downstaging the tumor and increasing the eligibility for breast-conserving surgery (BCS). The primary aim of this study was to assess the rate of BCS after NAC, and the secondary aim was to identify predictors of application of BCS after NAC. This was an observational prospective cohort study of 226 patients in the SCAN-B (Clinical Trials NCT02306096) neoadjuvant cohort during 2014–2019. Eligibility for BCS was assessed at baseline and after NAC. Uni- and multivariable logistic regression analyses were performed using covariates with clinical relevance and/or those associated with outcome (BCS versus mastectomy), including tumor subtype, by gene expression analysis. The overall BCS rate was 52%, and this rate increased during the study period (from 37% to 52%). Pathological complete response was achieved in 69 patients (30%). Predictors for BCS were smaller tumor size on mammography, visibility on ultrasound, histological subtype other than lobular, benign axillary status, and a diagnosis of triple-negative or HER2-positive subtype, with a similar trend for gene expression subtypes. Mammographic density was negatively related to BCS in a dose-response pattern. In the multivariable logistic regression model, tumor stage at diagnosis and mammographic density showed the strongest association with BCS. The rate of BCS after NAC increased during the study period to 52%. With modern treatment options for NAC the potential for tumor response and BCS eligibility might further increase.