title: Extent of Baseline Prostate Atrophy Is Associated With Lower Incidence of Low- and High-grade Prostate Cancer on Repeat Biopsy.
abstract: OBJECTIVE
  To evaluate whether baseline prostate atrophy (PA) extent is associated with prostate cancer (PCa) incidence at 2-year repeat prostate biopsy in a clinical trial with systematic biopsies.
  
  
  METHODS
  We performed a retrospective analysis of 3165 men 50-75 years old with prostate-specific antigen between 2.5 and 10 ng/mL and a prior negative biopsy in the placebo arm of the Reduction by Dutasteride of PCa Events trial who underwent a 2-year repeat biopsy. PA extent was defined as the percentage of cores with atrophic changes. The association of baseline PA with positive 2-year biopsies was evaluated with logistic regression in uni- and multivariable analysis, controlling for baseline covariates.
  
  
  RESULTS
  PA involving none, 1%-25%, 26%-50%, 51%-75%, and >75% of the baseline cores was observed in 966 of 3165 (30.5%), 1189 of 3165 (37.6%), 677 of 3165 (21.4%), 209 of 3165(6.6%), and 124 of 3165 (3.9%) cases, respectively. More extensive PA was associated with older age, lower prostate-specific antigen, larger prostate volume, and higher prevalence of acute and chronic inflammations (all P < .05). Compared to subjects without PA, those with 1%-25%, 26%-50%, 51%-75%, and >75% core involvement had an odds ratio for PCa of 0.65 (95% confidence interval [CI] = 0.52-0.81), 0.60 (95% CI = 0.46-0.78), 0.56 (95% CI = 0.37-0.86), and 0.35 (95% CI = 0.19-0.67), respectively. In multivariable analysis, the extent of PA was independently associated with lower PCa risk (P < .001). More extensive PA was associated with lower incidence of low-grade (Gleason 2-6) and high-grade (Gleason 7-10) PCa.
  
  
  CONCLUSIONS
  The extent of baseline PA is independently associated with lower PCa risk in a dose-dependent fashion.
authors.affiliation: Institute of Urology, University of Southern California, Los Angeles, CA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Freitas
authors.affiliation: Division of Urologic Surgery, Washington University School of Medicine, St. Louis, MO.
authors.forename: Gerald L
authors.initials: GL
authors.lastname: Andriole
authors.affiliation: GlaxoSmithKline Inc., Global R&D, King of Prussia, Pennsylvania, PA.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Castro-Santamaria
authors.affiliation: Division of Urology, Department of Surgery, Cedars Sinai Medical Center, Los Angeles, CA.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Freedland
authors.affiliation: Department of Urology, University of Illinois at Chicago, Chicago, IL. Electronic address: moreira@uic.edu.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Moreira
mesh_terms: D000368:Aged; D001284:Atrophy / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000473:pathology; D001706:Biopsy / Q000379:methods / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000032:analysis; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D018570:Risk Assessment; D012307:Risk Factors; D013223:Statistics as Topic; D047368:Tumor Burden
chemical_list: D017430:Prostate-Specific Antigen