JSM 2011 Online Program

The views expressed here are those of the individual authors and not necessarily those of the JSM sponsors, their officers, or their staff.

Abstract Details

Activity Number: 70
Type: Contributed
Date/Time: Sunday, July 31, 2011 : 4:00 PM to 5:50 PM
Sponsor: Biopharmaceutical Section
Abstract - #301417
Title: A Comparison of Longitudinal and Time-to-Endpoint Approaches for Treatment Comparisons in Tumor Growth Studies
Author(s): Kingshuk Roy Choudhury*+ and Ian Kasman and Greg D. Plowman
Companies: University College Cork and Genentech Inc. and Genentech Inc.
Address: Statistics Department, Cork, n/a, Ireland
Keywords: xenograft ; time to endpoint ; logrank test ; growth curve modelling ; censoring
Abstract:

Xenograft experiments test the efficacy of new therapies for various forms of human cancer by implanting human tumor tissue fragments in mice. Mice are randomised into treatment groups. The growth of these fragments into tumors is monitored over time till the end of the study or until the tumor reaches a preset volume threshold. Due to the presence of type I censoring, efficacy comparisons across treatment groups are traditionally carried out using time to endpoint (TTE) analyses such as log rank tests (Stutschke et al. 1990). However such tests can lack power under increased levels of type I censoring, caused by early termination of the experiment. An alternative analysis approach is via longitudinal growth curve modelling. Using simulation and analysis, we do a relative power comparison of these approaches under varying levels of type I censoring. With low levels of censoring (< 25%), the TTE based method is superior, while with higher levels of censoring ( > 60%), the longitudinal method is superior. The implications are illustrated in the context of a multi-armed study for non small cell lung cancer.


The address information is for the authors that have a + after their name.
Authors who are presenting talks have a * after their name.

Back to the full JSM 2011 program




2011 JSM Online Program Home

For information, contact jsm@amstat.org or phone (888) 231-3473.

If you have questions about the Continuing Education program, please contact the Education Department.