Comparison between perioperative and postoperative chemotherapy after potentially curative hepatic resection for metastatic colorectal cancer.

Background: Additional chemotherapy in patients with resectable colorectal liver metastases (CRLM) likely improves outcomes. Whether to administer chemotherapy as perioperative or adjuvant therapy remains controversial. We analyzed outcomes between these two treatment strategies.
Methods: Patients were identified from a prospective CRLM database and studied retrospectively. Patients with extrahepatic disease or initially unresectable CRLM were excluded. Only patients receiving oxaliplatin- and/or irinotecan-containing chemotherapy regimens were included. Univariate and Cox regression models were developed for recurrence and death.
Results: Between 1998 and 2007, 236 patients (57.4 %) in the adjuvant group and 175 patients (42.6 %) in the perioperative group were compared. The perioperative group was younger and had more tumors, shorter disease-free intervals, and higher clinical risk scores (CRS), but had smaller tumors. The overall survival was similar between the groups (perioperative 72.9 months vs. adjuvant 71.5 months; p = 0.48). When the comparison was adjusted for other clinicopathologic factors and CRS, the differences remained insignificant. On univariate analysis, there was a significant difference in recurrence-free survival between the groups (perioperative 17.2 months vs. adjuvant 27.4 months, p = 0.036). However, when the recurrence-free survival was adjusted for other clinicopathologic factors and the CRS, differences were not significant.
Conclusions: The timing of additional chemotherapy for resectable CRLM is not associated with outcomes. Trials comparing adjuvant and perioperative chemotherapy would have to be powered for small differences in outcome.