progression-free survival
Also written as: PFS — Progression-Free Survival
Clinical endpoint measuring time from treatment start until disease progression or death, whichever occurs first.
Full Definition
Progression-free survival (PFS) is a standardized clinical trial endpoint that measures the length of time from the start of treatment until documented disease progression or death from any cause, whichever occurs first. PFS serves as a surrogate endpoint for overall survival in many hematologic malignancy studies, particularly when crossover between treatment arms or subsequent therapies may confound overall survival analysis. The endpoint requires precise definition of disease progression criteria, typically based on standardized response criteria such as International Working Group guidelines. PFS analysis employs Kaplan-Meier methodology and is often presented as median survival times with confidence intervals.
Usage
Usage note: Hyphenate as compound modifier; capitalize when referring to specific endpoint
In Context
- "The median progression-free survival was 24 months in the experimental arm versus 12 months in controls." — Clinical trial primary analysis
- "Progression-free survival served as the primary endpoint for the randomized phase III study." — Study protocol description