Sample size estimation in phase III cancer clinical trials

This paper deals with the basic principles involved in sample size calculat ion of phase III cancer clinical trials. It illustrates the concepts and fa ctors determining the sample size. Various examples of phase III cancer cli nical trials are provided and the sample size is calculated taking into acc ount the assumptions made. The examples provided include sample sizes for c omparing proportions and sample sizes for comparing survival times, Several special topics are also discussed including choice of endpoint, number of treatment groups, factorial designs and equivalence trials.