5-alpha-reductase inhibitors (5ARIs), such as finasteride and dutasteride, reduce prostate size and PSA levels, potentially influencing PSA density (PSAD) measurements. This study evaluated how 5ARIs affect PSAD in patients undergoing active surveillance (AS) for prostate cancer and whether these changes correlate with disease progression to Grade Group 2 (GG2+) or the need for treatment. Using an IRB-approved database, researchers analyzed data from 445 patients undergoing MRI-ultrasound (MRI-US) fusion biopsies, with 47 patients identified as having taken 5ARIs. PSAD was assessed before starting, during, and after stopping 5ARIs, alongside progression rates to GG2+ disease or treatment.
Results showed that median PSAD before, during, and after 5ARI use was 0.106, 0.109, and 0.079, respectively. Among patients on 5ARIs, progression rates to GG2+ and treatment were 26% and 23% annually over the first two years of AS, compared to 31% and 19% for patients not on 5ARIs. Notably, patients on 5ARIs who progressed to GG2+ disease had significantly higher PSADs (median 0.139) than those who did not progress (median 0.074, p=0.013). Similarly, patients who progressed to treatment had higher PSADs (median 0.190) compared to those remaining on AS (median 0.074, p=0.006).
These findings indicate that while 5ARIs reduce PSAD, patients with clinically significant disease maintain elevated PSADs, offering a potential marker for identifying progression. The integration of MRI-US fusion biopsy enhances accuracy in monitoring these changes. Further research is required to establish PSAD thresholds for biopsy in patients on 5ARIs, improving risk stratification during AS
