Copy Number Alterations Of P53, Rb1, And Mdm2 As Prognostic Markers In Intermediate-Risk Prostate Cancer.

117 Background: We interrogated copy number alternations (CNA) of p53, Rb1 and MDM2 as prognostic determinants of biochemical failure in localized intermediate-risk prostate cancer. Methods: Using Affymetrix Oncoscan array technology, we characterized copy number alterations (CNA) for 284 D’Amico-classified intermediate-risk prostate cancers. Of the 284 patients, 143 underwent image-guided radiotherapy (IGRT), while 141 underwent radical prostatectomy (RadP). Biochemical-relapse free survival (bRFS) was assessed as a clinical end-point, with biochemical failure defined using the Phoenix and AUA criteria for IGRT and RadP patients, respectively. Results: We observed allelic losses ofp53 and Rb1 in 23.9% (n = 68) and 31.0% (n = 88) and allelic gains of MDM2 in 3.17% (n = 9) in our cohort, respectively. 7.7% (n = 22), 1.1% (n = 3) and 0.4% (n = 1) of all cases exhibited concurrent losses of p53 and Rb1, p53 loss and MDM2 gain, and concurrent p53/Rb1 loss and MDM2 gain, respectively. Patients with allelic los...