title: Finasteride reduces the risk of incident clinical benign prostatic hyperplasia.
abstract: BACKGROUND
  Despite the high prevalence of clinical benign prostatic hyperplasia (BPH) among older men, there remains a notable absence of studies focused on BPH prevention.
  
  
  OBJECTIVE
  To determine if finasteride prevents incident clinical BPH in healthy older men.
  
  
  METHODS
  Data for this study are from the Prostate Cancer Prevention Trial. After excluding those with a history of BPH diagnosis or treatment, or an International Prostate Symptom Score (IPSS) ≥ 8 at study entry, 9253 men were available for analysis.
  
  
  METHODS
  The primary outcome was incident clinical BPH, defined as the initiation of medical treatment, surgery, or sustained, clinically significant urinary symptoms (IPSS >14). Finasteride efficacy was estimated using Cox proportional regression models to generate hazards ratios (HRs).
  
  
  CONCLUSIONS
  Mean length of follow-up was 5.3 yr. The rate of clinical BPH was 19 per 1000 person-years in the placebo arm and 11 per 1000 person-years in the finasteride arm (p<0.001). In a covariate-adjusted model, finasteride reduced the risk of incident clinical BPH by 40% (HR: 0.60; 95% confidence interval, 0.51-0.69; p<0.001). The effect of finasteride on incident clinical BPH was attenuated in men with a body mass index ≥ 30 kg/m(2) (p(interaction) = 0.04) but otherwise did not differ significantly by physical activity, age, race, current diabetes, or current smoking. The post hoc nature of the analysis is a potential study limitation.
  
  
  CONCLUSIONS
  Finasteride substantially reduces the risk of incident clinical BPH in healthy older men. These results should be considered in formulating recommendations for the use of finasteride to prevent prostate diseases in asymptomatic older men.
authors.affiliation: Division of Urologic Oncology, Moores Comprehensive Cancer Center and Section of Urology, San Diego Veterans Affairs Medical Center, University of California, San Diego, La Jolla, CA 92093-0987, USA. jkparsons@ucsd.edu
authors.forename: J Kellogg
authors.initials: JK
authors.lastname: Parsons
authors.forename: Jeannette M
authors.initials: JM
authors.lastname: Schenk
authors.forename: Kathryn B
authors.initials: KB
authors.lastname: Arnold
authors.forename: Karen
authors.initials: K
authors.lastname: Messer
authors.forename: Cathee
authors.initials: C
authors.lastname: Till
authors.forename: Ian M
authors.initials: IM
authors.lastname: Thompson
authors.forename: Alan R
authors.initials: AR
authors.lastname: Kristal
mesh_terms: D058891:5-alpha Reductase Inhibitors / Q000627:therapeutic use*; D000368:Aged; D000369:Aged, 80 and over; D018120:Finasteride / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood; D011470:Prostatic Hyperplasia / Q000517:prevention & control*; D012306:Risk; D016896:Treatment Outcome
chemical_list: D058891:5-alpha Reductase Inhibitors; D018120:Finasteride; D017430:Prostate-Specific Antigen