Prostate Cancer Incidence in Patients on 5α-Reductase Inhibitors for Lower Urinary Tract Symptoms: A 14-Year Retrospective Study

Abstract

There is still much debate regarding the long-term effect of 5α-reductase inhibitors (5-ARI) on the development of prostate cancer (PC). We tested the incidence of prostate cancer and the tumour Gleason grading in a non-screened population who were prescribed 5-ARIs for lower urinary tract symptoms (LUTS). Data from a prostatic biopsy database were analysed in a retrospective study, and included a period of 14 years (01/01/1997 to 01/01/2011). Those patients who were on 5-ARIs with either finasteride or dutasteride for less than 1 year were excluded. Patients who presented with LUTS and underwent diagnostic prostatic biopsies were included in this study. This patient cohort was further categorised according to their history of 5-ARIs medication. The incidence of PC in the 5-ARI treated group was 15.4% ( n = 22/143), comparable to that of the untreated group (16.7%, n = 332/1990) ( p = 0.7318). Mean Gleason sum score and respective grade was the same (7 = 3 + 4) (median sum score 7 (range 6–10)). Average age at the time of PC diagnosis was similar regardless of 5-ARIs treatment: 72 (range 50–84) and 73 (45–84) years for treated and untreated groups, respectively. In this retrospective study, patients treated with 5-ARIs for LUTS had similar risk in developing PC when compared to those who did not receive 5-ARIs. The Gleason sum scores for the cancers were similar in the two groups.