Up to 50% of patients with colorectal cancer (CRC) develop liver metastasis during the course of their disease. In 30-40% of patients metastasis is confined to the liver. In these patients R0-resection of metastases may contribute to marked improvement of overall survival. Primary resection of liver metastasis is possible in about 15-20% of patients (Scheele 2005, Petrelli 2005). Recent studies indicate that perioperative chemotherapy may improve survival after resection of liver metastases (Portier 2007, Nordlinger 2007). Nevertheless, there is evidence that 70-80% of patients have recurrent disease after resection of liver metastasis. Stratification for the risk of recurrence may be performed using the FONG-score (Fong 1999).