Enhanced recovery and survival after elective surgery for colorectal cancer - propensity score weighting analysis of 2,865 prospective patients

Background: The impact of enhanced recovery pathway (ERP) on survival after colorectal cancer surgery (CCS) remains controversial. Materials and methods: A total of 2865 adults enrolled in a multicenter cohort study (iCral3 study) after CCS were followed up. The percentage adherence to the ERP was recorded, and the patients were grouped according to their quartiles. Other patient-, center-, disease-, and treatment-related factors were considered in a machine learning generalized boosted model (GBM) to estimate the 22 covariates propensity score weights for the binary comparisons between the reference treatment (1st quartile, ERP adherence rates <57.7 %) and the other treatment arms (2nd, 3rd, and 4th quartile). The primary endpoint was overall survival (OS). A GBM-weighted Cox model balanced on the same covariates was used to estimate the hazard ratio (HR) and 95 % confidence interval (95 %CI). Results: Patients in the 4th quartile (ERP adherence rates ≥80.8 %) showed a significant lower risk of death from any cause (HR, 0.69; 95 %CI 0.49-0.96; p = 0.026). Conclusions: High adherence to ERP was associated to a significant impact on long-term overall survival, supporting the efforts towards proper ERP implementation after CCS.