progression-free survival
Also written as: PFS — Progression-Free Survival
The length of time during and after treatment that a cancer patient lives without disease progression or death.
Full Definition
Progression-free survival (PFS) is a key endpoint in cancer clinical trials measuring the time from randomization or treatment initiation until objective tumor progression or death from any cause, whichever occurs first. PFS is determined using standardized imaging criteria such as RECIST and is considered clinically meaningful as it reflects the direct anti-tumor effect of treatment. Unlike overall survival, PFS is not influenced by subsequent therapies, making it a valuable measure of treatment efficacy, particularly in studies where crossover between treatment arms occurs.
Usage
Usage note: Hyphenate when used as a compound modifier; specify the time point when reporting rates.
In Context
- "The median progression-free survival was 8.2 months in the experimental arm versus 4.1 months in the control arm." — Clinical trial results
- "Progression-free survival at 12 months was significantly improved with the addition of maintenance therapy." — Efficacy analysis report