Impact of preoperative chemotherapy on overall survival for borderline resectable colorectal liver metastases

Abstract

365 Background: Treatment for borderline colorectal liver metastases (CLM) is often started with chemotherapy. However, the impact on overall survival (OS) is still unknown. Aims: The aim of this study is to analyze the impact of preoperative chemotherapy on the outcome for up-front resectable borderline CLMs (BLR-CLM). Methods: A retrospective review was performed of 169 patients who underwent liver resection of BLR-CLM among 510 patients underwent liver resection for CLM between 2005 and 2013. BLR-CRLM was defined as CRLM of four or more nodules or 5cm or larger nodule. Time to surgical failure (TSF) was defined as the time until unresectable relapse or death. OS, recurrence free survival (RFS) and TSF were compared between BLR-CLM treated with neoadjuvant chemotherapy (NAC) and up-front surgery (US). Results: After median follow-up period of 38 months, 5-year survival rate after liver resection of resectable cases (n = 263), BLR-CLM (n = 169), and initially unresectable CLM (n = 78) are 67.7%, 47.5% and 32.6%, respectively. For patients with BLR-CLM, 22 patients with early recurrence during or early after postoperative chemotherapy for the primary were excluded. In the remaining 147 patients, 75 patients were treated with NAC and 72 with US. Cumulative 5-year overall survival rates, progression free survival rates, and time-to surgical failure in NAC and US group are as follows: OS (60.1% vs 47.7%, p = 0.084), PFS (23.1% vs 15.5%, p < 0.0001), TSF (38.0% vs 34.4%, p = 0.020). Conclusions: Preoperative chemotherapy for BLR-CLM could improve PFS and TSF. The impact on OS was still marginal. Prospective controlled study will be necessary.