Does conversion chemotherapy really improve survival in patients with colorectal liver metastases

435 Background: Recently, liver resection becomes possible by intensive chemotherapy, i.e. conversion chemotherapy, in patients with initially unresectable colorectal liver metastases (CLM). But the criteria for non-resectability varies one team to another, and there are few reports about the clinical benefit of conversion chemotherapy followed by liver resection. Methods: Our criteria for resectability of CLM depends on the size of remnant liver volume (>30%) and expected function after the removal of all metastases, regardress of number and size of CLM. From December 2007 to September 2011, 113 patients were diagnosed as CLM without extra-hepatic metastases and received chemotherapy. 47 patients were initially diagnosed as resectable and received hepatic resection after chemotherapy (resected group). 66 patients were initially diagnosed as unresectable, but 11 patients become resectable after chemotherapy (conversion group) and 55 patients remain unresectable in spite of chemotherapy (unresecetd group)....