Total intravenous or inhalational volatile anaesthesia and survival after colorectal cancer surgery: a Swedish national registry study

Summary Introduction Retrospective studies suggest that inhalational volatile anaesthetic agents may contribute to an increased risk of metastasis and reduction in survival rates when used during cancer surgery. This relationship may vary between cancer types due to different tumour biology and differences in surgical procedures. This study aimed to investigate the relationship between the type of anaesthetic used for maintenance of anaesthesia (propofol or inhalational volatile anaesthetic agent) and survival in patients with stage 1–3 colorectal cancer who underwent resection surgery under general anaesthesia in Sweden between 2014 and 2019. Methods We identified patients from the Swedish Colorectal Cancer Registry. Their data, including cancer characteristics and adjuvant treatment, were then merged with information from the Swedish Peri‐operative Registry. The primary outcome was overall survival, with disease‐free survival as a secondary outcome. Results Of the 11,598 patients included, 8161 had colon cancer and 3437 had rectal cancer. General anaesthesia was maintained with propofol in 2346 (20%) patients, while 9252 (80%) received an inhalational volatile anaesthetic agent. In the unmatched cohort, patients who had general anaesthesia maintained with propofol for colon cancer surgery showed improved survival compared with those receiving an inhalational volatile anaesthetic agent (hazard ratio 0.83, 95%CI 0.72–0.95, p = 0.008). After 1:2 propensity score matching, we observed no significant difference in survival rates in this group (hazard ratio 0.89, 95%CI 0.76–1.04, p = 0.127). In the rectal cancer group, there was no difference in survival in either the unmatched cohort (hazard ratio 0.83, 95%CI 0.65–1.08, p = 0.166) or after propensity score matching (hazard ratio 0.95, 95%CI 0.71–1.25, p = 0.702). There was no significant difference in disease‐free survival in either type of cancer. Discussion We found no association between the choice of agent for maintenance of anaesthesia and long‐term survival outcomes in patients with colorectal cancer.