Validation of GEMCaP as a DNA Based Biomarker to Predict Prostate Cancer Recurrence after Radical Prostatectomy

Purpose: We aimed to validate GEMCaP (Genomic Evaluators of Metastatic Cancer of the Prostate) as a novel copy number signature predictive of prostate cancer recurrence.Materials and Methods: We randomly selected patients who underwent radical prostatectomy at Cleveland Clinic or University of Rochester from 2000 to 2005. DNA isolated from the cancer region was extracted and subjected to high resolution array comparative genomic hybridization. A high GEMCaP score was defined as 20% or greater of genomic loci showing copy number gain or loss in a given tumor. Cox regression was used to evaluate associations between the GEMCaP score and the risk of biochemical recurrence.Results: We report results in 140 patients. Overall 38% of patients experienced recurrence with a median time to recurrence of 45 months. Based on the CAPRA-S (Cancer of the Prostate Risk Assessment Post-Surgical) score 39% of the patients were at low risk, 42% were at intermediate risk and 19% were at high risk. The GEMCaP score was high (...