title: Exploring and validating surrogate endpoints in colorectal cancer.
abstract: Sargent et al (J Clin Oncol 23: 8664-8670, 2005) concluded that 3-year disease-free survival (DFS) can be considered a valid surrogate (replacement) endpoint for 5-year overall survival (OS) in clinical trials of adjuvant chemotherapy for colorectal cancer. We address the question whether the conclusion holds for trials involving other classes of treatments than those considered by Sargent et al. Additionally, we assess if the 3-year cutpoint is an optimal one. To this aim, we investigate whether the results reported by Sargent et al. could have been used to predict treatment effects in three centrally randomized adjuvant colorectal cancer trials performed by the Japanese Foundation for Multidisciplinary Treatment for Cancer (JFMTC) (Sakamoto et al. J Clin Oncol 22:484-492, 2004). Our analysis supports the conclusion of Sargent et al. and shows that using DFS at 2 or 3 years would be the best option for the prediction of OS at 5 years.
authors.affiliation: Center for Statistics, Hasselt University, Agoralaan D, 3590 Diepenbeek, Belgium. tomasz.burzykowski@uhasselt.be
authors.forename: Tomasz
authors.initials: T
authors.lastname: Burzykowski
authors.forename: Marc
authors.initials: M
authors.lastname: Buyse
authors.forename: Greg
authors.initials: G
authors.lastname: Yothers
authors.forename: Junichi
authors.initials: J
authors.lastname: Sakamoto
authors.forename: Dan
authors.initials: D
authors.lastname: Sargent
mesh_terms: D015415:Biomarkers / Q000032:analysis*; D015179:Colorectal Neoplasms; D006801:Humans; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D015203:Reproducibility of Results
chemical_list: D015415:Biomarkers