Tumor suppressor aberrations and outcomes in localized and metastatic hormone sensitive prostate cancer (PrCa).

184Background: Aberrations of tumor suppressors (TS) TP53, PTEN and RB1 are recurrent genomic events in PrCa and associated with adverse clinical outcomes. Preclinical data suggest that cooperative functional loss of these genes drives development of even more aggressive disease phenotypes. Methods: We identified a retrospective cohort of men with PrCa who underwent DFCI Oncopanel targeted sequencing (NGS) on prostate gland (n = 230) or metastatic tissue (n = 7) for TP53, PTEN and RB1. Biomarker(BM)-positive was defined as copy number loss or likely deleterious mutation of ≥1 TS. For pts presenting with localized disease, Kaplan-Meier method estimated time from biopsy preceding local therapy to PSA relapse/metastasis/death (EFS), castration resistance (CRPC) and death (OS). Cox model assessed association of BM status and outcomes, adjusted for age, clinical stage and Gleason score in multivariate analyses (MVA). For M1 disease, time from ADT start to CRPC and death was estimated. We explored the associati...