Prognostic factors and therapeutic effects of different treatment modalities for colorectal cancer liver metastases

BACKGROUND Colorectal cancer (CRC) is one of the most common malignant tumors in China, and the liver is the most common metastatic site in patients with advanced CRC. Hepatectomy is the gold standard treatment for colorectal liver metastases. For patients who cannot undergo radical resection of liver metastases for various reasons, ablation therapy, interventional therapy, and systemic chemotherapy can be used to improve their quality of life and prolong their survival time. AIM To explore the prognostic factors and treatments of liver metastases of CRC. METHODS A retrospective analysis was conducted on 87 patients with liver metastases from CRC treated at the Liaoning Cancer Hospital and Institute between January 2005 and March 2011. According to different treatments, the patients were divided into the following four groups: Surgical resection group (36 patients); ablation group (23 patients); intervention group (15 patients); and drug group (13 patients). The clinicopathological data and postoperative survival of the four groups were analyzed. The Kaplan-Meier method was used for survival analysis, and the Cox proportional hazards regression model was used for multivariate analysis. RESULTS The median survival time of the 87 patients was 38.747 +/- 3.062 mo, and the 1- and 3-year survival rates were 87.5% and 53.1%, respectively. The Cox proportional hazards model showed that the following factors were independent factors affecting prognosis: The degree of tumor differentiation, the number of metastases, the size of metastases, and whether the metastases are close to great vessels. The results of treatment factor analysis showed that the effect of surgical treatment was better than that of drugs, intervention, or ablation alone, and the median survival time was 48.83 +/- 4.36 mo. The drug group had the worst prognosis, with a median survival time of only 13.5 +/- 0.7 mo (P < 0.05). For patients with liver metastases of CRC near the great vessels, the median survival time (27.3 mo) of patients undergoing surgical resection was better than that of patients using other treatments (20.6 mo) (P < 0.05). CONCLUSION Patients with a low degree of primary tumor differentiation, multiple liver metastases (number of tumors > 4), and maximum diameter of liver metastases > 5 cm have a poor prognosis. Among drug therapy, intervention, ablation, and surgical treatment options, surgical treatment is the first choice for liver metastases. When liver metastases are close to great vessels, surgical treatment is significantly better than drug therapy, intervention, and ablation alone.