Correlative analysis between two commercially available post-prostatectomy genomic tests.

backgroundMultiple genomic tests are available following radical prostatectomy (RP), however, there is a lack of head-to-head evidence for these tests. We sought to compare the performance of two genomic tests in predicting post-RP oncological outcomes.

methodsA cohort of 16 post-RP patients with adverse pathological features who had obtained both Decipher (D) and Prolaris (P) testing. The Pearson correlation was used to compare scores from D and cell cycle progression (CCP) from P. Then, we derived a microarray CCP (mCCP) from D and correlated with P-CCP. The associations of D and mCCP with biochemical recurrence (BCR) and metastasis (M) was evaluated in multivariable survival analysis (MVA) in a large cohort of RP patients treated at Johns Hopkins University (1992-2010). In addition, we characterized the expression of the 31 P-CCP genes and mCCP scores in a cohort of 17,967 RP samples from Decipher platform.

resultsThere was significant correlation between the D score and P-CCP (r = 0.67, p = 0.004), and between the 10-year probability of BCR reported by P and 5-year probability of M reported by D (r = 0.69, p = 0.003). In this cohort, mCCP derived from the D platform was highly correlated to the reported P-CCP scores from the P platform (r = 0.88, p = 6.7e-6). In a comparative retrospective RP cohort, both mCCP and D were significantly associated with M outcome (p < 0.01 for both). On MVA, D was a predictor of M (HR 1.3, 95% CI [1.12-1.52], p = 0.0005), while mCCP was not a predictor of M (p = 0.62). In the D platform cohort, the 31 P-CCP genes were correlated to each other, and TOP2A was the most correlated to mCCP (r = 0.7).

conclusionsWe found that P and D scores post-RP were correlated and help in identifying patients who at high risk of BCR in this cohort. In a larger cohort with longer follow-up, D was predictor of M, whereas mCCP was not.