| [ Summary ] |
The surgical outcome for colorectal cancer treatment has improved over the last twenty five years. In order to get more improvement in survival treatment of liver metastases is important. Liver metastases develop in 25% of colorectal cancer patients (15% synchronously and 10% metachronously). There have been several reports on the natural history of liver metastases from colorectal cancer. Wood reported that the median survival of patients with liver metastases who had no treatment ranged from 3.1 months to 16.7 months and their survival depended on the extension of liver metastasis. Scheele stated that there was a median survival time of 14.2 months in patients whose liver metastasis was resectable but not resected.Hematogenous metastases from colorectal cancer may follow the cascade hypothesis described by Weiss: first hematogenous metastases develop in the liver, then in the lung, followed by systemic metastases. According to this theory, there is a step during hematogenous metastases where the metastases confine to the liver. Complete removal of liver metastases at this time can cure the disease. The main purpose of surveillance after surgery for colorectal cancer is to improve the prognosis through early detection of resectable liver metastases. Although a standard surveillance system has not been established yet, tumor marker examination, liver ultrasound or CT examination every 3 months, up to 2 years after surgery and every 6 months up to 3 years and tumor marker examinations every 6 months up to 5 years are recommended. |