Objective: To identify risk factors associated with overall survival (OS) for patients undergoing primary hepatic resection for metastatic colorectal cancer.
Methods: The clinical and pathological data were prospectively collected from 191 consecutive patients undergoing primary hepatic resection for colorectal liver metastases from January 2000 to August 2012. The survival curve was drawn by Kaplan-Meier method, and the survival rates were analyzed by Log-rank test. Parametric survival analysis was used to identify predictors of cancer-specific survival.
Results: The 5-year overall survival were 38.4% and median survival time was 33 months; 5-year disease-free survival were 23.6%, and the median disease-free survival time was 10.0 months. 5-years survival rate was significantly lower in patients with synchronal metastasis than in patients with heterochronia metastasis (27.4% vs. 51.8%, χ(2) = 6.527, P < 0.05). In overall survival, univariate analysis found 7 risk factors: gender (χ(2) = 5.219), N stage of the primary tumor (χ(2) = 5.591), bilobar metastases (χ(2) = 4.269), number of metastases ≥ 2 (χ(2) = 5.051), disease-free interval ≥ 6 months (χ(2) = 6.527), carcinoembyonic antigen level ≥ 30 µg/L (χ(2) = 4.454), and extrahepatic disease (χ(2) = 5.158). On multivariate analysis, 3 risk factors were found to be independent predictors of poor survival: N stage of the primary tumor (RR = 2.198, 95%CI: 1.146-4.216), disease-free interval ≥ 6 months (RR = 1.840, 95%CI: 1.139-2.973), carcinoembyonic antigen level ≥ 30 µg/L(RR = 1.854, 95%CI: 1.056-3.255).
Conclusions: Resection of liver metastases provides good long-term cancer-specific survival benefit. N stage of the primary tumor, disease-free interval, carcinoembyonic antigen level are important prognostic factors for colorectal liver metastasis.