Active Surveillance Selection and 3-Year Durability in Intermediate-Risk Prostate Cancer Following Genomic Testing - Beyond the Abstract
Confidently knowing whether to pursue active surveillance or definitive treatment is critical, as inappropriately choosing active surveillance means the prostate cancer may worsen, while unnecessarily choosing definitive treatment means suffering avoidable treatment-associated adverse events.
Literature is increasingly noting that patients with intermediate-risk localized prostate cancer can pursue active surveillance without substantially risking their prostate cancer worsening or metastasizing. Many tools help providers and individuals with prostate cancer predict a person’s prostate cancer risk level, including changes in prostate-specific antigen (PSA), Gleason scores, and risk guides like the University of California, San Francisco’s Cancer of the Prostate Risk Assessment (CAPRA) score and National Comprehensive Cancer Network’s risk guides (NCCN). More recently, genomic classifier prognostic tests have arisen as a means of increasing confidence in prostate cancer risk assessment. Prolaris is one such genomic classifier; it relies on a combined clinical risk score (CCR) that is the combination of a molecular-based cell-cycle progression score and the CAPRA risk score. This CCR score allows the Prolaris test results to deliver a personalized treatment recommendation based on whether the CCR score is below or above the Prolaris active surveillance threshold.
Our study evaluated individuals with intermediate-risk prostate cancer and their initial treatment decision after receiving Prolaris test results. We also looked at how likely patients who chose active surveillance based on Prolaris treatment recommendations are to have remained on active surveillance at three years of follow-up.
We evaluated 3,208 men with intermediate-risk prostate cancer. Individuals for whom Prolaris recommended active surveillance were twice as likely to choose active surveillance as those for whom Prolaris recommended to definitive therapy (p<0.0001), demonstrating significant clinical utility as a decision-making aid. Specifically, Prolaris identified 45.8% of patients (N = 1,470) as candidates for active surveillance, and 41.8% (N = 615) of these patients chose to pursue active surveillance. In contrast, of the 54.2% of patients (N = 1,738) Prolaris identified as candidates for definitive therapy, only 20.7% (N = 360) chose active surveillance. A bivariable logistic regression model showed that the Prolaris treatment recommendation was significantly associated with the decision to pursue active surveillance over definitive therapy, even after accounting for CAPRA score (p <0.0001).
At three years of follow-up, individuals were about 1.5 times more likely to still be on active surveillance if Prolaris initially recommended them to active surveillance, rather than definitive therapy (p<0.0001). Notably, multivariable Cox proportional hazard analyses showed that the Prolaris treatment recommendation remained significantly associated with durability of active surveillance, even after accounting for CAPRA score or NCCN risk category (p<0.0001 and p=0.0007, respectively).
This study underscores the importance of confidence in risk stratification for assisting prostate cancer patients and their providers with shared-decision making. Our findings demonstrate that individuals were more likely to pursue active surveillance when it was recommended by Prolaris. Moreover, individuals for whom Prolaris recommended active surveillance were 1.5 times more likely to continue active surveillance at 3 years of follow up.
Acknowledgements: The authors would like to thank Katherine Schultz, MD, for assistance with the production of this commentary.
Written by: Lauren Lenz, Christina Nakamoto, & Robert Finch, Myriad Inc., Salt Lake City, UT
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