Use of a 17-gene prognostic assay in contemporary urologic practice: results of an interim analysis in an observational cohort

Abstract Objective To study the impact of genomic testing in shared decision making for men with clinically low risk prostate cancer (PCa). Methods Patients with clinically low-risk PCa were enrolled in a prospective, multi-institutional study of a validated 17-gene tissue-based RT-PCR assay (Genomic Prostate Score™; GPS). In this manuscript we report on outcomes in the first 297 patients enrolled in the study with valid 17-gene assay results and decision-change data. The primary endpoints were shared decision on initial management and persistence on active surveillance (AS) at one year post-diagnosis. AS utilization and persistence were compared to similar endpoints in a group of patients who did not have genomic testing (baseline cohort). Secondary endpoints included perceived utility of the assay and patient decisional conflict before and after testing. Results One-year results were available on 258 patients. Shift between initial recommendation and shared decision occurred in 23% of patients. Utilization of AS was higher in the GPS-tested cohort than in the untested baseline cohort (62% vs 40%). The proportion of men who selected and persisted on AS at one year was 55% and 34% in the GPS and baseline cohorts, respectively. Physicians reported that GPS was useful in 90% of cases. Mean decisional conflict scores declined in patients after GPS testing. Conclusions Patients who received GPS testing were more likely to select and persist on AS for initial management compared to a matched baseline group. These data indicate that GPS help guide shared decisions in clinically low-risk PCa.