Comparison of overall survival after liver resection based on the independent significant prognostic factors. (A) Regional lymph node(s) metastasis. (B) Primary extrahepatic metastasis. (C) Synchronous versus metachronous metastases. (D) Grade of liver metastasis. (E) Resection margin of hepatectomy. Kaplan-Meier survival curves were plotted and examined by log-rank test between the two groups.