[Does PCA3 score and prostatic MRI help selection of patients scheduled for initial prostatic biopsy?]. / Le score PCA3 et l'IRM prostatique permettent-ils de sélectionner les patients candidats a une première série de biopsies prostatiques ?

ABSTRACT

INTRODUCTION: Determinate if the adjunction of PCA3 score and/or prostatic MRI can improve the selection of the patients who have an indication of first prostate biopsy. PATIENTS AND METHODS: Multiparametric prostatic MRI and PCA3 score were made before biopsy to men scheduled for initial prostate biopsy for abnormal digital rectal examination and/or PSA superior to 4 ng/mL. T2-weighted imaging, diffusion-weighted imaging and dynamic contrast-enhanced imaging looked for suspect target classified on a scale of four. It was a prospective, single centre study. The diagnostic accuracy of PCA3 score and MRI was to evaluate in comparison with biopsy results. RESULTS: Sixty-eight patients were included, median PSA was 5.2 ng/mL (3.2-28). Negative predictive value (NPV) of MRI score 0, 1 and 2 were respectively 80%, 43% and 69%. Positive predictive value (PPV) of MRI score 3 and 4 were 50% and 81%. The PCA3 cutoff with best accuracy was 21 (Se 0.91; Sp 0.50). Only one patient with positive biopsy (0.5mm of Gleason score 3+3) had negative MRI and PCA3 inferior to 21. CONCLUSION: MRI and PCA3 score in association allowed, in this study, to consider reduction of unnecessary initial biopsy without ignoring potential aggressive tumor.