[The role of a single PCA3 test before a first negative prostate biopsy: 5-year follow-up]. / Intérêt du test PCA3 avant une première série de biopsies prostatiques négatives : 5 ans de suivi.

ABSTRACT

PURPOSE: We report a 5-year follow-up of a cohort of patients who underwent a first prostate biopsy following a prostate cancer antigen 3 (PCA3) test. MATERIAL AND METHODS: We reviewed consecutive patients who had in 2008 a single urinary PCA3 test using the Gen-Probe® assay before a first prostate biopsy for a prostate-specific antigen (PSA) between 3 and 20ng/mL and/or a suspicious digital rectal examination. PCA3 performances were analyzed in 2008 and then in 2013 after taking into account the results of repeat biopsies. RESULTS: At initial biopsy in 2008, among the 125 patients study cohort, prostate cancer was diagnosed in 47 patients (37.6%). Abnormal digital rectal exam, PSA density, prostate volume and PCA3 score were significantly associated with prostate cancer diagnosis. PCA3 area under the curve of the receiver operating curve was 0.67 [95%CI 0.57-0.76] with an optimal threshold of PCA3 in this sample of 24 units. During the 5-year follow-up, among the 78 patients with a negative prostate biopsy in 2008, 23 (29.5%) had a repeat prostate biopsy of whom 14 were diagnosed with prostate cancer. PCA3 score measured in 2008 was associated with prostate cancer diagnosis (P=0.002). All 9 patients with a negative repeat prostate biopsy had a PCA3 score below the cut-off while this was the case in only 2 patients among the 14 with a positive repeat prostate biopsy. CONCLUSIONS: The results of a single PCA3 test before a first prostate biopsy seems to be a useful aid in deciding whether to perform a repeat biopsy. LEVEL OF EVIDENCE 4.