Urinary PCA3 to predict prostate cancer in a cohort of 1015 patients

Abstract

Aim: To evaluate the performance of urinary PCA3 test to predict prostate biopsy outcome in a large French cohort.

Patients and methods: A urine sample was prospectively obtained in 1015 patients undergoing prostate biopsies to determine the PCA3 score. The predictive value of PCA3 was explored using receiver operating characteristic curve analysis (ROC), multivariable logistic regression analysis and decision curve analysis.

Results: The median PCA3 score was significantly higher in patients with positive biopsies. The PCA3 score AUC was 0.76 (0.73-0.79), significantly higher than that of PSA (0.55; 0.51-0.58). At the cut-off of 35, sensitivity was 68 %, specificity 71 %, positive and negative predictive values 67 % and 71 %, and accuracy 69 %. Using multivariate analysis, PCA3 score appeared as an independent predictor of biopsy outcome and its addition to a base model including usual clinico-biological parameters resulted in a significant increase in predictive accuracy. At the cut-off of 20, about 1/2 of the eventual useless biopsies would have been avoided while ignoring 7 % of cancers with Gleason score ≥ 7. PCA3 score did not correlate to Gleason score but correlated to tumor volume (proportion of invaded cores).

Conclusion: Urinary PCA3 is a useful test with high diagnostic performance for early prostate cancer diagnosis. Its correlation with cancer aggressiveness seems rather represented by a link to prostate volume than Gleason score.

Keywords: Biopsies prostatiques; Cancer de la prostate; Diagnosis; Diagnostic; PCA3; Prediction; Prostate biopsies; Prostate cancer; Prédiction; Test urinaire; Urinary test.