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

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.

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.

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.

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.