progression-free survival
Clinical trial endpoint measuring time from treatment initiation to disease progression or death, whichever occurs first.
Full Definition
Progression-free survival (PFS) is a clinical trial endpoint that measures the length of time during and after treatment that a patient lives with the disease without it getting worse. PFS is calculated from the start of treatment until the first documented disease progression according to predefined criteria (such as RECIST) or death from any cause. This endpoint is commonly used in oncology clinical trials as it can be assessed earlier than overall survival and may correlate with clinical benefit. In oncology informatics, accurate PFS calculation requires precise capture of treatment start dates, imaging assessment schedules, and progression determination criteria.
Usage
Usage note: Hyphenate when used as a compound modifier. Abbreviate as 'PFS' after first mention in scientific documents.
In Context
- "The primary endpoint was progression-free survival as determined by independent central review." — Clinical trial protocol
- "Median progression-free survival was 8.2 months in the experimental arm versus 4.1 months in the control arm." — Clinical study report