Head-To-Head Comparison Between Decipher And Prolaris Tests: Two Commercially Available Post-Prostatectomy Genomic Tests

348 Background: Several post-prostatectomy genomic tests are available; which are used to improve prognostication and to guide additional treatment after radical prostatectomy (RP). There has been no head to head comparison between these tests. The objective of this study is to compare the performance of two genomic tests in predicting oncological outcomes. Methods: 16 patients who underwent RP at the University of Pennsylvania (UPenn) (2013-2018), had adverse pathology (margin, and/or pT3a/b) and had each been tested with both Decipher (D) and Prolaris (P). Pearson correlation was used to compare scores from D and P as well as CCP scores and microarray derived CCP (mCCP). The associations of D and P with biochemical recurrence (BCR) and metastasis (M) was evaluated in survival analysis in a large cohort of RP patients treated at Johns Hopkins University (1992-2010) (JHU). Results: The median follow-up of the UPenn cohort was 24 months. 6 patients developed BCR and two distant M. There was a significant correlation between the D and P score (r=0.67,p=0.004), and between the 10-year BCR risk reported by P and the 5-year M risk reported by D (r=0.69, p=0.003). Each test called 7 patients to be high risk; 5 were in common. Both tests correctly called the 2 M cases as high risk and 4/6 BCR patients to be high risk. A microarray-derived CCP (mCCP) was highly correlated to the CCP scores reported from P (r=0.88, p=6.7e-6) in the UPenn cohort. To compare the prognostic performance of mCCP to D for predicting BCR and M, we used Post-RP cohort from JHU (N=355). Both scores were correlated (r=0.36, p2e-12). D and mCCP were stratified into 5 groups of incremental 20%. When including mCCP groups, D groups, Gleason score, SVI, EPE, LNI, and PSA; D remained independent prognostic variable of BCR (HR 1.16, 95%CI [1.05-1.3], p=0.005) and M (HR 1.3, 95%CI [1.12-1.52], p=0.0005). However, mCCP was not prognostic of BCR (p=0.59) nor M (p=0.62). Conclusions: The findings from this study show that P and D scores post-RP were highly correlated and help in identifying patients who at high risk of progression in this small cohort with short follow up. However, D outperformed mCCP for predicting BCR and M in larger cohorts with longer follow up.