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). We assessed the survival benefit between these 3 groups, retrospectively. Results: 110 patients received oxaliplatin-based regimen and 3 irrinotecan-based regimen. In coversion group, 8 patients received cetuximab containing regimen and 2 received bevacizumab containing regimen. 46 of 47 patients in resected group received R0 resection and 7 of 11 patients in conversion group. No serious postoperative complications were observed in resected and conversion group, but the incidence of a surgical site infection in conversion group was somewhat higher than in resected group. Median disease-free survival was significantly higher in the resected group than conversion group (16.73 months [95% CI: 7.80~25.47] and 3.83 months [95% CI: 0.35~7.31 months]) (P=0.031). And median overall survival (OS) was also higher in resected group, but not significant. In resected and conversion group, median OS was significantly higher than in unresected group. (52.20 vs 39.37 vs 20.57 months (p <0.001)). Conclusions: The recurrence rate was higher in coversion group, but conversion chemotherapy followed by hepatic resection seems to be promising and feasible strategy in initially unresectable CLM patients.
Bilobar spreading of colorectal liver metastases does not significantly affect survival after R0 resection in the era of interdisciplinary multimodal treatment
