title: The impact of PSA and digital rectal examination on the risk of prostate cancer specific mortality in men with a PSA level <2.5 ng/ml.
abstract: BACKGROUND
  It is unknown whether a normal range, diagnostic serum prostate specific antigen (PSA) level's influence on prostate cancer specific mortality (PCSM) is dependent upon digital rectal examination (DRE) findings.
  
  
  METHODS
  Between 2004 and 2007, 9081 men diagnosed with non-palpable (T1c, N=1710) or palpable (T2-T4, N=7371) and non-metastatic prostate cancer (PC) were identified from surveillance, epidemiology, and end results data, selected based on pre-treatment PSA<2.5 ng/ml. A multivariable competing risks regression model evaluated whether DRE findings interacted with PSA level in predicting risk of PCSM.
  
  
  RESULTS
  After median follow-up of 2.83 years, 118 of 548 deaths (21.5%) were due to PC. Increasing diagnostic PSA was associated with increased risk of PCSM (AHR=3.52; 95% CI: 1.25-9.89; P=.017) in men with T1c, Gleason score 7-10 PC, but decreased PCSM risk (AHR=0.66; 95% CI: 0.52-0.83; P<.001) for men with T2-T4 PC and any Gleason score.
  
  
  CONCLUSIONS
  For men with diagnostic PSA level <2.5 ng/ml and palpable PC, risk of early PCSM increases by 34% for a 1 point decrease in PSA from 2. This suggests the existence of clinically detectable, low PSA secreting disease with an elevated risk of early PCSM, highlighting the importance of the DRE in men with PC and normal range, diagnostic PSA.
authors.affiliation: Department of Radiation Oncology, Brigham and Women's Hospital, Dana Farber Cancer Institute, Boston, MA, USA. Electronic address: ipashtan@partners.org.
authors.forename: Itai
authors.initials: I
authors.lastname: Pashtan
authors.affiliation: Department of Statistics, University of Connecticut, Storrs, CT, USA.
authors.forename: Ming-Hui
authors.initials: MH
authors.lastname: Chen
authors.affiliation: Department of Radiation Oncology, Brigham and Women's Hospital, Dana Farber Cancer Institute, Boston, MA, USA.
authors.forename: Anthony V
authors.initials: AV
authors.lastname: D'Amico
mesh_terms: D000368:Aged; D051517:Digital Rectal Examination; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D012044:Regression Analysis; D012306:Risk
chemical_list: D017430:Prostate-Specific Antigen
keywords: Digital rectal examination; Low PSA; Prostate cancer; Prostate cancer specific mortality; SEER program