title: Utility of PSA doubling time in follow-up of untreated patients with localized prostate cancer.
abstract: OBJECTIVE
  To evaluate the prostate-specific antigen (PSA) changes and the ability of PSA doubling time (PSADT) to predict disease progression in untreated patients with clinically localized prostate cancer.
  
  
  METHODS
  A total of 104 patients with localized prostate cancer were followed up expectantly with serial PSA measurements and digital rectal examination (DRE). PSADT was calculated by linear regression analysis for the 94 patients who had a minimum of three PSA measurements and 12 months of follow-up. The median follow-up was 33 months. Of the 94 patients, 45 underwent repeat prostate biopsy to evaluate whether tumor progression occurred during the observation period.
  
  
  RESULTS
  Twenty-seven percent of patients had rapid PSADTs (less than 48 months). Only the presence of palpable disease on DRE correlated with a PSADT of less than 48 months (P <0.05). However, a PSADT of less than 120 months consistently correlated with disease progression on DRE and on repeat biopsy, as well as with the presence of clinically significant cancer. PSADT did not correlate with the Gleason score. Furthermore, patients with a PSADT of less than 48 months did not differ significantly from those with a PSADT of 48 to 120 months with regard to Gleason score, disease progression on DRE or on repeat biopsy, and the presence of significant cancer.
  
  
  CONCLUSIONS
  A PSADT of less than 120 months correlates with disease progression. However, its clinical utility remains limited to identify patients at risk of disease progression reliably.
authors: Department of Surgery (Urology), McGill University, Montreal, Ontario, Canada.
authors: Andrew J
authors: AJ
authors: Stephenson
authors: Armen G
authors: AG
authors: Aprikian
authors: Luis
authors: L
authors: Souhami
authors: Hassan
authors: H
authors: Behlouli
authors: Avrum I
authors: AI
authors: Jacobson
authors: Louis R
authors: LR
authors: Bégin
authors: Simon
authors: S
authors: Tanguay
mesh_terms: D001706:Biopsy; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D016014:Linear Models; D008297:Male; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology
chemical_list: D017430:Prostate-Specific Antigen