Differential microRNA expression in epithelial cell populations from human prostate: its relevance to treatment resistance in prostate cancer

Since prostate cancer is a heterogeneous disease both between patients and at the cellular level, within patients, all population studies result in a median value for whatever parameter is being measured. Genome sequencing (and phenotyping) have contributed massively to the resolution of inter-patient heterogeneity, defining patient groups according to treatment response, clinical grade and of course genomic fingerprint, but nevertheless statistical outliers persist. Is this because cancer is inherently heterogeneous, with several pathways capable of resulting in a final aggressively growing and invasive phenotype, or is it because sophisticated studies are still being carried out on heterogeneous mixtures of cells?