(Dallas—March 10, 2022, 3:21 p.m.) — Recurrence-free survival (RFS) has been used as a surrogate endpoint for overall survival (OS) in trials involving resectable colorectal liver metastasis (CRLM). However, according to research presented at the Society of Surgical Oncology 2022 International Conference on Surgical Care, recurrence-free survival is an inadequate surrogate for overall survival.
According to presenter Brett Ecker, MD, from Memorial Sloan Kettering Cancer Center in New York, the correlation between recurrence-free survival and overall survival has not been previously examined in a clinical context.
Dr. Ecker and his team analyzed 2,983 patients who underwent complete resection of colorectal liver metastasis between 1991 and 2019 at one cancer center and followed the patients for an average of 8.4 years.
Overall survival and recurrence-free survival probabilities at various timepoints were estimated and simulated randomized trials with homogenous arms were performed to evaluate the within-trial concordance of RFS and OS.
Of the patients analyzed, there were 1,995 (67%) disease recurrences and 1,684 (56%) deaths. Median recurrence-free survival was 1.3 years (95% CI 1.3-1.4), and median overall survival was 5.2 years (95% CI 5.0-5.5). A total of 1,428 deaths (85%) were preceded by recurrence, and median time from recurrence to death was 2.0 years (range 0-23 years). Pairwise correlations between recurrence-free survival and overall survival were weak to moderate, with a correlation estimate ranging from 0.30-0.56, and maximized for the pair of 5-year RFS and 7-year OS (0.56, SD 0.13). Of the simulated randomized trials where a statistical difference in OS between trial arms was detected, only 29% also had a statistically different RFS between trial arms.
“Following resection of colorectal liver metastasis, we found minimal correlation between recurrence-free survival and overall survival,” Dr. Becker reported.