411P Laparoscopic versus open liver resection for colorectal cancer liver metastases: Five-year actual survival of the previously reported randomized controlled trial – The OSLO-COMET Trial

Abstract

Research on laparoscopic liver resection has shown shorter recovery time, a better quality of life, and fewer postoperative complications. Our previous report of the OSLO-COMET trial showed that laparoscopic surgery in patients with colorectal cancer liver metastases was equivalent to open resection regarding oncologic outcomes. The current report aimed to investigate the survival outcomes of this trial after a minimum follow-up of 6 years. Patients with resectable colorectal liver metastases from February 2012 to January 2016 were randomized between laparoscopic and open parenchyma-sparing liver resection with curative intent (ClinicalTrials.gov: NCT01516710). The trial's primary outcome was postoperative morbidity within 30 days, while overall survival was a predefined secondary endpoint. Patients received perioperative chemotherapy following Norwegian guidelines, at the discretion of the multidisciplinary team. Two hundred eighty patients were randomized to laparoscopic (n = 133) or open (n = 147) surgery. Current survival analysis was performed on January 20, 2022, with a minimum of 72 months follow-up and with a median follow-up of 94 months (95%CI, 91 to 97). Median overall survival was 71 months (95% CI 47 to 95) in the laparoscopic surgery group and 74 months (95%CI, 52 to 96) in the open surgery group (p=0.970), and the 5-year actual survival compiled 55% and 54%, respectively (HR 1.006 [0.738 to 1.372]). Median recurrence-free survival (RFS) was 17 months (95%CI, 10 to 23) after laparoscopy and 16 months (95%CI, 8 to 24) after open surgery, with a 5-year RFS of 33% and 31% (p = 0.705). These long-term outcomes after a minimum follow-up of six years, together with short-term results, further support the use of laparoscopic surgery to treat colorectal cancer liver metastases.