A sample selection strategy to boost the statistical power of signature detection in cancer expression profile studies.

ABSTRACT: In case-control profiling studies, increasing the sample size does not always improve statistical power because the variance may also be increased if samples are highly heterogeneous. For instance, tumor samples used for gene expression assay are often heterogeneous in terms of tissue composition or mechanism of progression, or both; however, such variation is rarely taken into account in expression profiles analysis. We use a prostate cancer prognosis study as an example to demonstrate that solely recruiting more patient samples may not increase power for biomarker detection at all. In response to the heterogeneity due to mixed tissue, we developed a sample selection strategy termed Stepwise Enrichment by which samples are systematically culled based on tumor content and analyzed with t-t

SUBMITTER: Jia Z 

PROVIDER: S-EPMC3786411 | biostudies-literature | 2013 Feb

REPOSITORIES: biostudies-literature