Early Detection Research Network

Longitudinal assessment of urinary PCA3 for predicting prostate cancer grade reclassification in favorable-risk men during active surveillance.

To assess the utility of urinary prostate cancer antigen 3 (PCA3) as both a one-time and longitudinal measure in men on active surveillance (AS).

The Johns Hopkins AS program monitors men with favorable-risk prostate cancer with serial PSA, digital rectal examination (DRE), prostate magnetic resonance imaging and prostate biopsy. Since 2007, post-DRE urinary specimens have also been routinely obtained. Men with multiple PCA3 measures obtained over ⩾3 years of monitoring were included. Utility of first PCA3 score (fPCA3), subsequent PCA3 (sPCA3) and change in PCA3 were assessed for prediction of Gleason grade reclassification (GR, Gleason score >6) during follow-up.

In total, 260 men met study criteria. Median time from enrollment to fPCA3 was 2 years (interquartile range (IQR) 1-3) and from fPCA3 to sPCA3 was 5 years (IQR 4-6). During median follow-up of 6 years (IQR 5-8), 28 men (11%) underwent GR. Men with GR had higher median fPCA3 (48.0 vs 24.5, P=0.007) and sPCA3 (63.5 vs 36.0, P=0.002) than those without GR, while longitudinal change in PCA3 did not differ by GR status (log-normalized rate 0.07 vs 0.06, P=0.53). In a multivariable model including age, risk classification and PSA density, fPCA3 remained significantly associated with GR (log(fPCA3) odds ratio=1.77, P=0.04).

PCA3 scores obtained during AS were higher in men who underwent GR, but the rate of change in PCA3 over time did not differ by GR status. PCA3 was a significant predictor of GR in a multivariable model including conventional risk factors, suggesting that PCA3 provides incremental prognostic information in the AS setting.

Carter HB, Elliott DJ, Epstein JI, Landis P, Mamawala M, Patel HD, Pavlovich CP, Ross AE, Sokoll LJ, Tosoian JJ, Wolf S

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Prostate Cancer Prostatic Dis., 2017, 20 (3)