Reconsideration of sample size and power calculation for overall survival in cancer clinical trials

Inkyung Jung, Hee Jung Ko, Sun Young Rha, Chung Mo Nam

Research output: Contribution to journalArticle

Abstract

When designing a cancer clinical trial, it is usual to assume an exponential distribution for a time-to-event outcome such as overall survival (OS). OS is often expressed as the sum of progression-free survival (PFS) and survival post-progression (SPP), each of which is assumed to be exponentially distributed. Then, OS does not follow an exponential distribution any more but a gamma or hypo-exponential distribution. In this study, we derived a sample size calculation formula for comparing OS between two treatment arms using the log-rank test for OS following a gamma or hypo-exponential distribution. We conducted a simulation study to evaluate the sample size and power calculation based on the gamma or hypo-exponential distribution. We found that we could reduce the sample sizes considerably compared to when assuming an exponential distribution for OS.

Original languageEnglish
Pages (from-to)90-91
Number of pages2
JournalContemporary Clinical Trials Communications
Volume12
DOIs
Publication statusPublished - 2018 Dec

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Sample Size
Clinical Trials
Neoplasms
Disease-Free Survival

All Science Journal Classification (ASJC) codes

  • Pharmacology

Cite this

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abstract = "When designing a cancer clinical trial, it is usual to assume an exponential distribution for a time-to-event outcome such as overall survival (OS). OS is often expressed as the sum of progression-free survival (PFS) and survival post-progression (SPP), each of which is assumed to be exponentially distributed. Then, OS does not follow an exponential distribution any more but a gamma or hypo-exponential distribution. In this study, we derived a sample size calculation formula for comparing OS between two treatment arms using the log-rank test for OS following a gamma or hypo-exponential distribution. We conducted a simulation study to evaluate the sample size and power calculation based on the gamma or hypo-exponential distribution. We found that we could reduce the sample sizes considerably compared to when assuming an exponential distribution for OS.",
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Reconsideration of sample size and power calculation for overall survival in cancer clinical trials. / Jung, Inkyung; Ko, Hee Jung; Rha, Sun Young; Nam, Chung Mo.

In: Contemporary Clinical Trials Communications, Vol. 12, 12.2018, p. 90-91.

Research output: Contribution to journalArticle

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