Risk Stratification Methods for Active Surveillance of Prostate Cancer

New Orleans—Many men with localized prostate cancer utilize active surveillance during treatment. A recent study presented by Jack Cuzick, PhD, during a session at the AUA 2015 Annual Meeting noted that better risk stratification is needed to appropriately select men for active surveillance.

The cell cycle progression (CCP) score is based on measuring the expression levels of CCP genes and has proven to be a solid predictor of prostate cancer outcomes in various clinical settings. In this study, the researchers presented a validation of an active surveillance threshold for a predefined score that combines CCP with CAPRA (CCR) in order to predict prostate cancer mortality in conservatively managed patients.

The study included 505 men who were tested in the researchers’ clinical laboratory. Based on their CCR score, these patients were determined to be considered for active surveillance. The training cohort included men with a Gleason score of three or less, a prostate-specific antigen score of less than 10 ng/mL, less than 25% cores positive, and a clinical stage of less than T2a. A threshold CCR score of 0.8 was selected so that 90% of men in the training cohort had scores below the threshold.

Performance characteristics were then evaluated in two independent cohorts: (1) TAPG1, n=180; and (2) TAPG2, n=585. Survival data were censored at 10 years.

The primary analysis was to evaluate the CCR threshold on TAPG2. Sixty men in the TAPG2 cohort were below the threshold in the validation cohort and the threshold validated, which divided the group into low and high risk (P=.0008). No deaths occurred in patients below the threshold. The Cox proportional hazard estimate of 10-year mortality associated with the CCR threshold was 3.3%, according to the study’s findings. The 10-year mortality risk associated with the threshold in the combined cohort of TAPG1 and TAPG2 was 3.2%.

The researchers concluded, “For patients considering deferred treatment, the CCR score provides significant prognostic information at disease diagnosis.” The CCR threshold can be used as a guide for patients appropriate for active surveillance treatment based on an integrated view of risk assessment provided in the study.

Source: Cuzick J, Stone S, Fisher G, et al. Validation of an active surveillance threshold for the CCP score in conservatively managed men with localized prostate cancer. Abstract of a presentation at the American Urological Association 2015 Annual Meeting, New Orleans, Louisiana, May 15, 2015.

This study was funded by Myriad Genetics, Inc.