Is Recurrence-Free Survival an Adequate Endpoint in Studies of Colorectal Liver Metastasis?

In adjuvant therapy trials of patients with resected colorectal liver metastases, recurrence-free survival (RFS) has been used as a surrogate for overall survival (OS), allowing for earlier interpretation of therapeutic outcomes. However, the correlation between RFS and OS in this disease setting has not been validated.

Now, investigators have conducted a retrospective, single-institution study spanning 30 years to evaluate the correlation between RFS and OS in 2983 patients who underwent curative hepatic resection for colorectal liver metastases. Nearly half of patients (46%) had left-sided primary tumors that were node-positive (62%), and most (63%) had one or two liver metastases resected that were synchronous with the primary cancer (56%). R0 resection was achieved in 88% of patients, 91% received additional systemic therapy, and 28% received adjuvant hepatic arterial infusion chemotherapy.

At a median follow-up of 8.4 years, 67% of patients had disease recurrence, with a median RFS of 1.3 years and a median OS of 5.2 years. Low correlation was found between RFS and OS. RFS was similar among patients evaluated earlier (between 1991 and 2000) and those evaluated later (between 2001 and 2019), but OS was superior in patients evaluated later.

The authors also assessed the correlation between RFS and OS in a meta-analysis of phase 3 adjuvant therapy trials involving 1185 patients with colorectal cancer undergoing hepatic resection. No correlation was observed between RFS and OS.