Prostate cancer (PCa) patients on active surveillance (AS) are monitored through repeated prostate-specific antigen (PSA) measurements, digital rectal exams (DREs) and prostate biopsies. A subset of AS patients will later "reclassify" with disease progression prompting definitive treatment. To minimize the risk of under-treating such AS patients, minimally-invasive tests incorporating biomarkers to identify patients who will reclassify are urgently needed.

We assessed post-DRE urine samples of AS patients for selected DNA methylation biomarkers that were previously investigated in radical prostatectomy specimens and shown to correlate with increasing risk of PCa. Post-DRE urine samples were prospectively collected from 153 men on AS who were diagnosed with Gleason Score (GS) 6 disease. Urinary sediment DNA was analyzed for eight DNA methylation biomarkers by multiplex MethyLight assay. Correlative analyses were performed on gene methylation and clinicopathological variables to test their predictive ability of patient risk-reclassification.

Using backward logistic regression, a four gene methylation "Classifier Panel"(APC, CRIP3, GSTP1, HOXD8) was identified. The Classifier Panel was able to predict patient reclassification (OR= 2.559; 95% CI= 1.257-5.212). We observed this panel to be an independent and superior predictor compared to current clinical predictors such as PSA at diagnosis or % of tumor positive cores in initial biopsy.

We demonstrate that a urine-based Classifier Panel of four methylation biomarkers predicts disease progression of AS patients. Once validated in independent AS cohorts, these promising biomarkers may help establish a less-invasive method for monitoring patients on AS programs.