Meta-analysis of clinical and quality of life outcomes following immediate and delayed autologous abdominal micro-vascular flap breast reconstruction in patients receiving adjuvant, neoadjuvant or no radiotherapy

Background Effects of post-mastectomy radiotherapy (PMRT) on autologous breast reconstruction (BRR) are controversial regarding surgical complications, cosmetic appearance and quality of life (QOL). This systematic review evaluated these outcomes after abdominal free flap reconstruction in patients undergoing post-operative adjuvant radiotherapy (PMRT), pre-operative radiotherapy (Neo RT) and no radiotherapy (RT), aiming to establish evidence-based optimal timings of RT and BRR to guide contemporary management. Methods Study has been registered on PROSPERO (CRD42017077945). Embase, MEDLINE, Google Scholar, CENTRAL, Science Citation Index, and clinicaltrials.gov were searched (January 2000 - August 2018). Study quality and bias-risk were assessed using GRADE and Cochrane’s ROBINS-I, respectively. Results Some 12 studies were identified, involving 1756 patients (350 PMRT, 683 no RT and 723 Neo RT), with a mean follow-up of 27.1 [range 12.0-54.0] (PMRT), 16.8 [1.0-50.3] (Neo RT) and 18.3 [1.0-48.7] (no RT) months. Three prospective and nine retrospective cohorts were included. There were no randomised studies. Comparative RT studies evaluated PMRT (n=5) and Neo RT (n=4). Studies were low quality, with moderate to serious bias-risks. Severe complications were similar between groups: PMRT (n=92) versus (vs) no RT (n=141), (Odds Ratio (OR) 2.35, 95% Confidence Interval (CI) 0.63-8.81), p=0.200; Neo RT (n=180) vs no RT (n=392) (OR 1.24, CI 0.76-2.04), p=0.390; or combined (PMRT and neo-adjuvant) RT (n=272) vs no RT (n=453) (OR 1.38, CI 0.83-2.32), p=0.220. QOL and cosmetic studies used inconsistent methodologies. Conclusion Evidence is conflicting and study quality was poor limiting recommendations for the timing of autologous BRR and RT. The impacts of PMRT or Neo RT seem similar