title: Why post-progression survival and post-relapse survival are not appropriate measures of efficacy in cancer randomized clinical trials.
abstract: Comparisons of post-relapse survival (PRS) and post-progression survival have been used to measure efficacy in some cancer clinical trials. These comparisons are an attempt to account for second-line therapies and to identify benefits that do not translate in longer overall survival. However, the use of PRS comparisons can be misleading (either a longer or shorter PRS may indicate a benefit, depending on the circumstances) and can result in biased estimates (because of selection). Here, we describe the problems surrounding PRS comparisons and propose alternative approaches to deal with non-randomized therapies administered after progression to the experimental treatment.
authors.affiliation: Department of Epidemiology, Harvard School of Public Health, Boston, MA.
authors.forename: Xabier
authors.initials: X
authors.lastname: García-Albéniz
authors.forename: Joan
authors.initials: J
authors.lastname: Maurel
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Hernán
mesh_terms: D018450:Disease Progression; D006801:Humans; D015233:Models, Statistical; D009364:Neoplasm Recurrence, Local / Q000401:mortality*; D009369:Neoplasms / Q000401:mortality* / Q000473:pathology; D016032:Randomized Controlled Trials as Topic; D016019:Survival Analysis
keywords: bias; clinical trials; post-progression survival; post-relapse survival