Salvage surgery after total neoadjuvant therapy and watch-and-wait in rectal cancer: a systematic review and proposed minimum outcome set

Abstract

Abstract Background Salvage surgery for local regrowth following watch-and-wait (W&W) after total neoadjuvant therapy (TNT) is perceived to be technically more difficult than immediate surgery after treatment. However, surgical difficulty lacks standardised definition and reporting. This methodological review proposes a structured minimum outcome set (MOS) to distinguish intra-operative technical complexity from surgery-related morbidity and evaluates current reporting against this framework. Methods A predefined framework comprised two domains: (1) surgery-related morbidity (Clavien–Dindo major complications, 30- or 90-day mortality, anastomotic leak, reoperation/readmission within 30 days and stoma status) and (2) intra-operative technical complexity (surgical approach, conversion, operative time, blood loss and a predefined pelvic complexity metric). R0/R1 resection status was recorded separately as a contextual oncological measure. A systematic review identified studies reporting salvage surgery for local regrowth after TNT and W&W. Reporting of MOS variables was enumerated and risk of bias assessed using a topic-specific ROBINS-I tool. Results Ten studies met the inclusion criteria, comprising 569 patients managed with TNT and W&W; 198 (35%) developed local regrowth and 172 (87%) underwent salvage surgery. Only one study reported major complications with salvage-specific denominators. Mortality, anastomotic leak, reoperation and stoma outcomes were absent or pooled. R0/R1 status was reported in seven studies but often without salvage-specific denominators. No study reported objective intra-operative metrics corresponding to predefined technical complexity variables. Risk of bias ranged from moderate to serious. Conclusions Current reporting is insufficient to define the safety or technical complexity of salvage surgery after TNT and W&W. The proposed MOS offers an exploratory basis for standardised reporting and may inform future consensus-driven core outcome set development.