RE: Some big shapes this morning…..at last!28 Jan 2026 17:53
FWIW
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What is the difference between event free and progression free survival
AI Overview:
Progression-Free Survival (PFS) measures the time from treatment initiation until objective tumor growth or death from any cause.
Event-Free Survival (EFS) measures the time from randomization until a broader range of "events," including disease progression, treatment failure, complications, or death.
PFS focuses on tumor growth; EFS focuses on any negative outcome.
Key Differences:
Definition of Event: PFS is restricted to disease progression or death.
EFS includes those, plus failure to proceed to planned surgery, relapse, or severe treatment complications.
Context of Use:
PFS is commonly used in advanced or metastatic cancer trials to evaluate treatment efficacy.
EFS is frequently used in earlier-stage cancer trials, particularly in the neoadjuvant (pre-surgery) setting.
Precision:
PFS depends on the frequency of imaging scans to detect growth, while EFS is often defined by the time until a patient cannot proceed with their treatment plan.
Essentially, PFS means the cancer has not worsened, whereas EFS means the patient has not experienced any negative, pre-defined event.