International Expert Consensus on Defining Textbook Oncologic Outcomes in Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy for Colorectal Peritoneal Metastasis

Textbook oncologic outcome (TOO) is a composite metric shown to correlate with improved survival following curative intent oncologic procedures. Despite increasing use among disciplines in surgical oncology, no consensus exists for its definition in cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC).An international consensus-based study employed a Delphi methodology to achieve agreement. Fifty-four senior surgeons from the peritoneal surface malignancies field received a questionnaire comprised of TOO parameters divided into 3 surgical domains: operative, short-term and long-term postoperative outcomes. Two online meetings with participants defined the new criteria. Consensus was achieved when 75% agreement rate was reached. Clinical data of patients who underwent CRS/HIPEC for colorectal peritoneal metastasis (CPM) between 2010-2022 from one designated center (SMC) were collected, the consensus definition applied and outcomes analyzed.Thirty-eight surgeons (70%) participated. Expert consensus TOO parameters for CPM-CRS/HIPEC included the absence of: unplanned re-operations during 30-days post-operation, severe postoperative complications (Clavien-Dindo≥III), unplanned readmissions during 30 days post-operation, 90-day postoperative mortality, and contraindications for chemotherapy within 12 weeks from operation, and included the achievement of complete cytoreduction (CC-0). The study cohort consisted of 251 patients; 151 patients (60%) met TOO criteria. Patients who achieved TOO had significantly better overall survival (median 67.5 months, CI 95%) vs patients who did not achieve TOO (median 44.6 months, CI 95%, p-value<0.001) and significantly improved disease-free survival (median, 12 months, CI 95%, vs. 9 months, CI 95%, p-value=0.01).Achievement of TOO as defined by consensus statement is associated with improved survival.