Gene expression data obtained at baseline will be analyzed in order to investigate the relationship between the gene expression and the following: CTCs, mpMRI imaging parameters, histopathological tumor parameters, and biochemical/clinical failure.
CTC changes between baseline and 2-2.5 years will be compared with 2-2.5 year biopsy positivity status (positive vs. negative) for patients whose baseline and 2-2.5 year biopsy samples are available. CTC changes from two different time points will be tested for significance using t-test by 2-2.5 year biopsy positivity status. Changes in gene expression and imaging parameters will be analyzed in the same manner. Correlation structures between CTC and imaging parameters; CTC and gene expression; and imaging parameters and gene expression will be analyzed using linear mixed-effect model by 2-2.5 year biopsy positivity status.