Perioperative risk factors for survival outcomes in elective colorectal cancer surgery: a retrospective cohort study

BACKGROUND: Surgical resection remains the best option for long-term survival in colorectal cancer (CRC); however, surgery can lead to tumor cell release into the circulation. Previous studies have also shown that surgery can affect cancer cell growth. The role of perioperative factors influencing long-term survival in patients presenting for CRC surgery remains to be investigated. METHODS: This retrospective single–center cohort study was conducted to collect the clinical data of patients who underwent elective laparoscopic resection for CRC from January 2014 to December 2015, namely clinical manifestations, pathological results, and perioperative characteristics. Survival was estimated using the Kaplan–Meier log-rank test. Univariable and multivariable Cox regression models were used to compare hazard ratios (HR) for death. RESULTS: A total of 234 patients were eligible for analysis. In the multivariable Cox model, tumor-node-metastasis (TNM) stage (stage IV: HR 30.63, 95% confidence interval (CI): 3.85–243.65; P = 0.001), lymphovascular invasion (yes: HR 2.07, 95% CI 1.09–3.92; P = 0.027), inhalational anesthesia with isoflurane (HR 1.96, 95% CI 1.19–3.21; P = 0.008), and Klintrup–Makinen (KM) inflammatory cell infiltration grade (low-grade inflammation: HR 2.03, 95% CI 1.20–3.43; P = 0.008) were independent risk factors affecting 5-year overall survival after laparoscopic resection for CRC. CONCLUSIONS: TNM stage, lymphovascular invasion, isoflurane, and KM grade were independent risk factors affecting CRC prognosis. Sevoflurane and high-grade inflammation may be associated with improved survival in CRC patients undergoing resection.