Validation of GEMCaP as a DNA based biomarker to predict disease recurrence in patients undergoing prostatectomy for prostate cancer.

58Background: There are currently no validated DNA based biomarkers available for routine clinical use to predict prostate cancer recurrence after prostatectomy. The Genomic Evaluators of Metastatic Cancer of the Prostate (GEMCaP) assay is a tumor genotype using copy number for a set of genomic loci. We aim to validate the GEMCaP assay using an external cohort of intermediate and high risk patients. Methods: We randomly identified 203 patients who had undergone radical prostatectomy at the Cleveland Clinic (CC) and University of Rochester (UR) from 2000-2005. DNA from macrodissected cancer tissues were subjected to high resolution array comparative genomic hybridization (aCGH) using Agilent’s oligonucleotide microarray platform. A high GEMCaP score was defined as > 20% of the genomic loci exhibiting copy number gain or loss in a given tumor. Cox regression was used to evaluate associations between the GEMCaP score and risk of biochemical recurrence in univariate and multivariate analyses adjusted for the ...