Prognostic factors of overall survival in patients with recurrent disease following liver resection for colorectal cancer metastases: A multicenter external validation study

BACKGROUND: The clinical course of patients experiencing recurrence following hepatectomy for colorectal cancer metastases (CRM) is poorly defined. Previous studies associated shorter time to recurrence (TTR) in months, node-positive primary tumor, and more than one site of recurrence with worse outcomes. METHODS: We conducted a retrospective cohort study across four Canadian institutions to externally validate previously established prognostic factors of overall survival (OS). We included consecutive adult patients who had a recurrence following curative-intent liver resection for CRM. Prognostic factors were explored using a multivariable Cox regression model. Risk group cutoffs were identified through recursive partitioning. OS between low- and high-risk groups was compared using the Kaplan-Meier method. RESULTS: This study included 471 patients. Shorter TTR in months (hazard ratio [HR]: 0.95, 95% confidence interval [CI]: 0.93-0.97), presence of extrahepatic disease at first hepatectomy (HR: 2.54, 95% CI: 1.18-5.50), and larger tumor size in millimetres (HR: 1.01, 95% CI: 1.00-1.02) were associated with worse OS. Median OS in the high- and low-risk groups were 40.5 (95% CI: 34.0-45.7 months) versus 64.7 months (95% CI: 57.9-72.3 months; p < 0.001), respectively. CONCLUSIONS: We externally validated the prognostic significance of shorter TTR (<8.5 months) as a predictor of worse OS in patients who recur the following hepatectomy for CRM.