Evaluating and Adjusting for Premature Censoring of Progression-Free Survival

Abstract

The intent-to-treat principle, grouping subjects as they were randomized and following all subjects to the endpoint or the end of study, allows valid statistical comparisons. Progression-free survival (PFS) has been used as a decision-making endpoint in oncology. It can be difficult to have a meaningful intent-to-treat analysis of PFS as some studies have extensive loss to follow-up for PFS. In the analysis, subjects lost to follow-up for PFS have their PFS times censored, with the censoring treated as noninformative. We use remaining overall survival to investigate whether premature censoring for PFS is informative and the potential bias in treating such censoring as noninformative.

Key Words:

• Loss to follow-up
• Overall survival
• Progression-free survival

ACKNOWLEDGMENT

This research is supported by an internal grant, RSR #09-05 and #10-31. The views expressed in this article are those of the authors and do not necessarily represent those of the U.S. Food and Drug Administration. The work by Mei Jin and Haojin Zhou on this article was while they were interns at the FDA.

This article not subject to US copyright law.

Notes

¹Hazard ratios are LTF for PFS versus not LTF for PFS with no PFS event.

Note. Hazard ratios are experimental/control.

Note. Hazard ratios are experimental/control.

Note. Hazard ratios are experimental/control.