[BioC] How to determine sample size for second-stage experiments

[Qunyuan Zhang]

Hi,

We just finished an initial inverstigation (50000-gene Affymetrix, 15
cancered people and 10 normal people). 40 genes' RNA expressional levels
were found significantly different between the two groups (by two sample
t tests, p values corrected). We are now planning a second-stage
experiment to validate this finding. We want to do power analysis and
sample size calculation, especially want to know how many peoples should
be included in the second-stage experiment. 

Besides the function  Power.t.test(), is there any other functions in
any packages availabe in bioConductor for this kind of experimantal
design problems?    

Thanks,

Qunyuan Zhang