Abstract PO1-22-06: Pre-operative radiotherapy followed by mastectomy and breast reconstruction – a systematic review of oncological and reconstructive outcomes

Abstract

Abstract Background Pre-operative radiotherapy (PRT) followed by mastectomy and autologous breast reconstruction for locally advanced breast cancer has the potential to reduce the deleterious impact of radiotherapy on the reconstructed breast and expedite treatment without impact on oncologic control. The PRADA feasibility study (Lancet Oncol 2022; 23: 682-90) has previously demonstrated the technique is technically feasible and safe in modern breast oncology practice, however, there is a clear necessity for longer term outcome data to precisely determine clinical efficacy. In order to understand and appraise this evidence gap, we performed a systematic review focused on oncologic and reconstructive outcomes of PRT followed by mastectomy and breast reconstruction. Methods A prospectively registered search (PROSPERO ID: CRD42023349524) of Medline (Ovid), EMBASE (Ovid), EMCARE (Ovid) and CINAHL (EBSCO) databases was performed in August 2022 for studies reporting NART prior to mastectomy and breast reconstruction. Oncological and aesthetic outcomes were extracted with risk of bias (ROBINS-I) and methodological quality assessed (STROBE checklist) for each study. Results Twenty one published articles (18 papers and 3 abstracts) were identified reporting the outcomes of 1,126 patients with median follow-up between 19.0-212.4 months. Seventeen studies were non randomised single-centre cohort studies (12 retrospective and 5 prospective). Patients received neoadjuvant chemotherapy in 18 studies. The majority of studies were of low methodological quality and at serious risk of bias. Rates of locoregional recurrence and overall survival ranged between 0-21.7% and 79.8%-98.3% respectively. Rates of flap loss or necrosis ranged from 0-12.0%. Rates of revisional procedures ranged between 0-35.3%. Patient-reported outcomes were reported in 8 studies and were mostly ‘good’ or ‘excellent’. Conclusion The published literature described a heterogeneity of outcome for patients undergoing NART prior to mastectomy and breast reconstruction. This reflects a large number of small retrospective single-centre cohort studies of low methodological quality at risk of bias. There is a clear need for a prospective randomised controlled trial appraising the outcomes of PRT in the context of autologous breast reconstruction. Citation Format: Ken Ho, Joseph Ward, Chiugo Ike, Paul Thiruchelvam, Aadil Khan, Daniel Leff. Pre-operative radiotherapy followed by mastectomy and breast reconstruction – a systematic review of oncological and reconstructive outcomes [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-22-06.