Active surveillance selection and 3-year durability in intermediate-risk prostate cancer following genomic testing.

Background: Genomic testing can add risk stratification information to clinicopathological features in prostate cancer, aiding in shared medical decision-making between the clinician and patient regarding whether active surveillance (AS) or definitive treatment (DT) is most appropriate. Here we examined initial AS selection and 3-year AS durability in patients diagnosed with localized intermediate-risk prostate cancer who underwent Prolaris testing before treatment decision-making.

Methods: This retrospective observational cohort study included 3208 patients from 10 study sites who underwent Prolaris testing at diagnosis from September 2015 to December 2018. Prolaris utilizes a combined clinical cell cycle risk score calculated at diagnostic biopsy to stratify patients by the Prolaris AS threshold (below threshold, patient recommended to AS or above threshold, patient recommended to DT). AS selection rates and 3-year AS durability were compared in patients recommended to AS or DT by Prolaris testing. Univariable and multivariable logistic regression models and Cox proportional hazard models were used with molecular and clinical variables as predictors of initial treatment decision and AS durability, respectively.

Results: AS selection was ~2 times higher in patients recommended to AS by Prolaris testing than in those recommended to DT (p < 0.0001). Three-year AS durability was ~1.5 times higher in patients recommended to AS by Prolaris testing than in those recommended to DT (p < 0.0001). Prolaris treatment recommendation remained a statistically significant predictor of initial AS selection and AS durability after accounting for CAPRA or Gleason scores.

Conclusions: Prolaris added significant information to clinical risk stratification to aid in treatment decision making. Intermediate-risk prostate cancer patients who were recommended to AS by Prolaris were more likely to initially pursue AS and were more likely to remain on AS at 3 years post-diagnosis than patients recommended to DT.