Long-Term Survival Benefit and Potential for Cure after R1 Resection for Colorectal Liver Metastases

Background: Although efficient chemotherapy regimens have improved outcomes after R1 resection (positive margins) for colorectal liver metastases (CLMs), the long-term survival benefit and potential for cure after R1 resection have not been clearly demonstrated. The aim of this study was to evaluate the long-term outcome after R1 resection for CLM, and to identify factors predictive of cure. Methods: All resected CLM patients at our institution from 2000 to 2009 were prospectively evaluated. Cure was defined as a disease-free interval ≥5 years from the last hepatic or extrahepatic resection to last follow-up. Results: Of 628 patients consecutively resected for CLM, 428 were eligible for the study, of whom 219 (51 %) underwent R0 resection (negative margins) and 209 (49 %) underwent R1 resection. Overall, 130 patients with R0 resection and 141 patients with R1 resection had more than 5 years of follow-up. Five- and 10-year overall survival rates were 56 and 34 % for R0 patients, and 48 and 36 % for R1 patients, respectively (p = 0.37). Of the 141 patients who underwent R1 resection, 26 patients (18 %) were considered ‘cured’, and 106 patients (75 %) were considered ‘noncured’. Independent predictive factors of cure after R1 resection included ≤10 total cycles of preoperative chemotherapy and objective response to preoperative chemotherapy. Conclusions: Overall, potential cure can be achieved in 18 % of patients after R1 resection for CLM. The best conditions to achieve long-term survival after R1 resection rely on a good response to efficient and short first-line chemotherapy.