Prostate cancer antigen 3: diagnostic outcomes in men presenting with urinary prostate cancer antigen 3 scores ≥100.

Objective: To describe the results of 3 rounds of diagnostic testing and linkage to the Dutch Cancer Registry for men with an initial prostate cancer antigen 3 (PCA3) score ≥100.
Methods: Within an earlier reported comparative study of PCA3 vs prostate-specific antigen in a prescreened population, 90 men with a PCA3 score ≥100 were identified and underwent biopsy, 28 prostate cancers (PCs) were found, 62 men remained at risk of a diagnosis of PC. All men were offered repeat testing; 6 PCs were found in 20 men at rebiopsy. Men with at least 1 negative biopsy (n = 56) were invited to undergo magnetic resonance imaging (MRI) studies and MRI-guided biopsies if indicated. Linkage to the Dutch Cancer Registry after 2.8 years of follow-up was performed for men with negative biopsies.
Results: Of the 56 men at risk, 28 agreed to participate in further testing. They were offered MRI studies; only 7 men agreed, and in 2, suspicious lesions were found and biopsies carried out. Only 1 PC was diagnosed and classified as T1c, Gleason 3 + 3 = 6. The overall findings of 3 rounds of testing and of linkage to the cancer registry show that eventually 35 PCs were detected in 90 men with PCA3 scores ≥100 (positive predictive value 38.9%).
Conclusion: Finding no PC despite extended diagnostic efforts in many men with initial PCA3 scores ≥100 is unexpected and might be clinically relevant.
(Copyright © 2014 Elsevier Inc. All rights reserved.)