Pathological Patterns of Prostate Biopsy in Men with Fluctuations of Prostate Cancer Gene 3 Score: A Preliminary Report

Background: To evaluate pathological patterns of prostate biopsy in men with changes in risk class by prostate cancer gene 3 (PCA3) score and with elevated serum prostate-specific antigen (PSA) or positive digital rectal examination (DRE), undergoing a repeat biopsy. Patients and Methods: A total of 108 males of two Italian Institutions who had undergone at least two PCA3 score assessments with changed PCA3 risk class were selected. Comparison of PCA3 score in patients with negative re-biopsy [normal parenchyma, benign prostatic hyperplasia (BPH), chronic prostatitis, high-grade prostate intraepithelial neoplasia (HG-PIN), atypical small acinar prostate (ASAP)] or positive re-biopsy was performed. Results: The up-and down-grading rates for PCA3 score were 71.3% (n=77) and 28.7% (n=31), respectively. Among the 77 up-graded patients, the median change in PCA3 score was 24 (range=4-69), while among the 31 down-graded ones, the median change was 17 (2 to 55). The PCA3 score in 24 out of 29 (82.7%) patients with prostate cancer (PCa) was up-graded. No association was found for correlation of PCA3 score change with age >65 years (p=0.975), family history of prostate cancer (p=0.796), positive DRE (p=0.179), use of 5-alpha-reductase inhibitors (p=0.793) and BPH/prostatitis/HG-PIN/ASAP diagnosis (p=0.428). Conclusion: PCA3 score can be considered a marker that is stable over time in most cases; notably, up to 20% of patients have a clinically relevant change of risk class. The rate of PCa was higher in patients whose PCA3 score was up-graded, even if no robust cut-off for PCA3 score fluctuation was identified.