Preoperative Radiation Therapy and Immediate Breast Reconstruction, a phase 3 randomized controlled trial in the...

BACKGROUND: Currently there is a wide practice variation in breast reconstruction surgery after mastectomy for breast cancer patients, especially when radiation therapy (RT) is involved. While it is clear from the scientific literature that immediate implant-based reconstruction has an increased complication rate when postmastectomy Radiation therapy (PMRT) is administered, the jury is out on autologous immediate breast reconstructions (IBR). Nevertheless, some clinicians avoid autologous IBR due to aesthetic outcomes being negatively influenced by PMRT. Others only place tissue expanders, or avoid IBR altogether, when PMRT is indicated. This leads to prolonged periods of time where the patient must live without a new breast, inferior aesthetic outcomes, or an increase in complications. This phase 3 clinical trial, building on the PRADA pilot study, will investigate the efficacy and safety of preoperative RT combined with IBR. METHODS: In this open-label, multicentre, phase 3, randomised controlled trial, 180 female participants with a new diagnosis of breast cancer will be enrolled. Participants will be randomised into two groups. The first group (control) will receive the standard of care treatment (SoC) consisting of mastectomy followed by PMRT; in this group the breast reconstruction can be either delayed or immediate. The second group (experimental) consists of preoperative RT followed by mastectomy and IBR. After treatment conclusion, follow-up will take place at 3 months, 1, 2, 5, and 10 years after the last study treatment. The primary outcome is the patient reported outcome measure of satisfaction with breasts (BREAST-Q score) at 1 year of follow-up. Secondary outcomes include cosmetic assessment, quality of life, adverse events, treatment duration, and histopathology response rates, tertiary endpoints include oncological survival outcomes according to DATECAN definitions. The trial sponsor is ZAS vzw, and is funded by ‘Kom op tegen kanker’. DISCUSSION: Preoperative RT has been implemented in multiple other types of cancer and could offer an opportunity to improve aesthetic and quality of life outcomes in breast cancer patients. Based on the PRADA pilot study and similar research, no increase in adverse events or worse oncological outcomes is expected from this change in treatment sequence. TRIAL REGISTRATION: ClinicalTrials.gov: NCT06739655; First registration: 17-DEC-2024. Local ZAS Augustinus trial-ID: CTO23023GZA; First registration: 22-APR-2024.