Anaesthetic type and survival in metastatic colorectal cancer: a nationwide population-based study

Introduction The impact of anaesthetic choice on survival following metastatic cancer surgery is uncertain. Volatile anaesthetics such as sevoflurane may promote inflammation and tumour progression, while the intravenous propofol has been suggested to be anti-inflammatory. This study evaluated the association between anaesthetic maintenance agents (Inhalational vs. propofol) and overall survival in patients undergoing surgery for metastatic colorectal cancer (CRC). Method Adult patients (≥18 years) with metastatic CRC who underwent elective or emergency surgery from 2013 to 2018 were identified in the Swedish Colorectal Cancer Registry (SCRCR) and matched with the Swedish Perioperative Registry (SPOR). Propensity score matching (PSM) (2:1, inhalation:propofol), Kaplan-Meier (KM), and cox regression were used to assess survival. Result Of 1233 patients, 1011 received inhalational anaesthesia and 222 received propofol. Baseline characteristics were comparable including gender and median age of 70 in both groups. Cox regression analysis identified that overall survival was significantly associated with age, ASA, surgical urgency, and tumour location. PSM resulted in 642 patients (Inhalational: 428; propofol: 214). KM demonstrated comparable survival, with 1- and 3-year survival rates of 76.2% vs.72.6% and 45.8% vs. 41.5% for inhalation vs. propofol, respectively (p = 0.14). Cox regression analysis in the matched cohort also demonstrated no significant difference in overall survival (HR 1.19, p = 0.14). Discussion The choice of anaesthetic maintenance agent was not significantly associated with overall survival. However, poorer survival was independently associated with advanced age, higher ASA class, and right-sided tumours.