Urinary PCA3 as a predictor of prostate cancer in a cohort of 3,073 men undergoing initial prostate biopsy.

PURPOSE: PCA3 is a urinary marker that has shown promise in predicting the presence of prostate cancer in men undergoing repeat prostate biopsy. We studied PCA3 before initial prostate biopsy.

MATERIALS AND METHODS: Records from a single organization were retrospectively reviewed. The predictive value of PCA3 was explored using nonparametric receiver operating characteristic curve analysis (ROC) and multivariable logistic regression analysis.

RESULTS: A total of 3,073 men underwent PCA3 analysis before initial prostate biopsy sampling of 12 to 14 areas. Mean PCA3 was 27.2 and 52.5 for patients without and with cancer, respectively. Prostate cancer was identified in 1,341 (43.6%) men. Overall 54.5% had Gleason 6 disease and 45.5% had Gleason 7 or greater (high grade prostate cancer). Mean PCA3 was 47.5 and 58.5 for the patients with Gleason 6 and 7 or greater disease, respectively. On multivariable logistic analysis PCA3 was statistically significantly associated with prostate cancer and high grade prostate cancer after adjusting for prostate specific antigen (p<0.001 for both), free prostate specific antigen (p=0.04 and p=0.01, respectively), age (p<0.001 for both), family history (p<0.001 and p=0.59, respectively), abnormal digital rectal examination (p=0.31 and p<0.001, respectively), prostate volume (p<0.001 for both) and body mass index (p<0.001 for both). Using ROC analysis PCA3 outperformed prostate specific antigen in the prediction of prostate cancer (AUC 0.697 vs 0.599, p<0.01) but not for high grade prostate cancer (AUC 0.682 vs 0.679, p=0.702).

CONCLUSIONS: PCA3 proved a useful tool in identifying patients at risk for prostate cancer before initial prostate biopsy. To our knowledge this is the largest PCA3 study in the initial biopsy population. These results suggest that further exploration of the value of PCA3 is warranted.