Effects of anesthesia on long-term survival in cancer surgery: A systematic review and meta-analysis

Backgrounds The association between anesthesia and long-term oncological outcome after cancer surgery remains controversial. This study aimed to investigate the effect of propofol-based anesthesia and inhalation anesthesia on long-term survival in cancer surgery. Methods A comprehensive literature search was performed in PubMed, Medline, Embase, and the Cochrane Library until November 15, 2023. The outcomes included overall survival (OS) and recurrence-free survival (RFS). The hazard ratio (HR) and 95 % confidence interval (CI) were calculated with a random-effects model. Results We included forty-two retrospective cohort studies and two randomized controlled trials (RCTs) with 686,923 patients. Propofol-based anesthesia was associated with improved OS (HR = 0.82, 95 % CI:0.76-0.88, P < 0.00001) and RFS (HR = 0.80, 95 % CI:0.73-0.88, P < 0.00001) than inhalation anesthesia after cancer surgery. However, these positive results were only observed in single-center studies (OS: HR = 0.76, 95 % CI:0.68-0.84, P < 0.00001; RFS: HR = 0.76, 95 % CI:0.66-0.87, P < 0.0001), but not in multicenter studies (OS: HR = 0.98, 95 % CI:0.94-1.03, P = 0.51; RFS: HR = 0.95, 95 % CI:0.87-1.04, P = 0.26). The subgroup analysis revealed that propofol-based anesthesia provided OS and RFS advantages in hepatobiliary cancer (OS: HR = 0.58, 95 % CI:0.40-0.86, P = 0.005; RFS: HR = 0.62, 95 % CI:0.44-0.86, P = 0.005), gynecological cancer (OS: HR = 0.52, 95 % CI:0.33-0.81, P = 0.004; RFS: HR = 0.51, 95 % CI:0.36-0.72, P = 0.0001), and osteosarcoma (OS: HR = 0.30, 95 % CI:0.11-0.81, P = 0.02; RFS: HR = 0.32, 95 % CI:0.14-0.75, P = 0.008) surgeries. Conclusion Propofol-based anesthesia may be associated with improved OS and RFS than inhalation anesthesia in some cancer surgeries. Considering the inherent weaknesses of retrospective designs and the strong publication bias, our findings should be interpreted with caution. Well-designed multicenter RCTs are still urgent to further confirm these findings.