CLINICOPATHOLOGICAL STUDY OF PROSTATE BIOPSY IN PATIENTS RECEIVING DUTASTERIDE FOR BENIGN PROSTATIC HYPERPLASIA

Dutasteride is a 5-alpha reductase inhibitor used to treat benign prostatic hyperplasia. Dutasteride lowers prostate-specific antigen (PSA) levels, which may lead to delays in the diagnosis and treatment of prostate cancer (PCa). This study investigated patients who underwent prostate biopsy (PBx) while receiving dutasteride to investigate whether this agent affects the diagnosis and treatment of PCa.PBx was performed on six patients receiving dutasteride for > 3 months at our medical institutions between January 2010 and June 2013. No patients underwent PBx before dutasteride administration. We performed PBx both for patients with high initial PSA levels and for those with elevated PSA levels with or without initial PSA decline after dutasteride administration. We also investigated clinicopathological findings.Mean age at the start of administration was 69.5 ± 5.9 years (range, 59-77 years), mean duration of administration was 14.1 ± 7.4 months (range, 4.0-23.5 months), mean prostate volume at the start of administration was 70.4 ± 30.7 ml (range, 18.8-104.6 ml), and mean PSA level at the start of administration was 7.7 ± 3.3 ng/ml (range, 4.9-14.2 ng/ml). PSA density was 0.098 ± 0.045 ng/ml/cm3 (range, 0.042-0.181 ng/ml/cm3), and PSA level at PBx was 5.4 ± 2.7 ng/ml (range, 2.5-10.7 ng/ml). We detected three PCa patients, and clinical stage in each case was cT1cN0M0. Radical retropubic prostatectomy was performed in two cases, and androgen-deprivation therapy was performed in one case.All PCa were detected in the early clinical stage. No delays in detection or treatment of PCa were seen in any cases. Careful observation of PSA levels is simple and useful for detecting PCa in patients under dutasteride administration.