Application of active surveillance threshold to series of samples submitted for commercial testing.

Abstract

84 Background: Active surveillance (AS) is an increasingly popular treatment modality for men with localized prostate cancer. Recently, we developed a method to select men for AS based on a score that combines cell cycle progression (CCP) with CAPRA (combined clinical CCP risk (CCR) score). Here, we apply our validated AS threshold to a series of samples submitted for commercial testing. Methods: Formalin-fixed prostate biopsy samples from 7,881 patients were submitted by their physicians to Myriad Genetic Laboratories for CCP analysis. Patient clinicopathological data was obtained from the test request form. The CCP score was calculated based on RNA expression of 31 CCP genes normalized to 15 housekeeping genes, and combined with CAPRA to generate the CCR score. The clinicopathological data of patients with a CCR score meeting the AS threshold were analyzed focusing on their PSA, % positive cores, Gleason, stage, AUA risk classification, and CAPRA score. Results: Of the 7,881 patients included in the analysis, 4,758 (60.4%) qualified for AS based on their CCR score. A substantial number of these patients, 2,213 (46.5%), would not have qualified for AS based on their clinical characteristics alone according to the following criteria: Gleason ≤ 3+4, PSA < 10, clinical stage ≤ T2a, and < 25% positive cores. A summary of the patients’ clinicopathological characteristics is shown below. Conclusions: This analysis showed that 60.4% of commercially tested patients qualified for AS, nearly half of which would not have qualified for AS based on their clinicopathological characteristics. For patients considering deferred treatment, the CCR score provides significant prognostic information at disease diagnosis. [Table: see text]