title: The role of urine prostate cancer antigen 3 mRNA levels in the diagnosis of prostate cancer among Hong Kong Chinese patients.
abstract: OBJECTIVE
  To establish and verify the utility of measuring urine prostate cancer antigen 3 (PCA3) mRNA levels in the diagnosis of prostate cancer among Hong Kong Chinese patients.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Urology Unit of a regional hospital in Hong Kong.
  
  
  METHODS
  This study was carried out in two parts. In the first part, 102 post-prostatic massage urine samples were collected from patients with known prostate cancer (38 patients) and controls (64 patients, with normal digital rectal examination and serum prostate-specific antigen <4 ng/mL). The urine levels of PCA3 and prostate-specific antigen mRNA were measured and the best cut-off point for differentiating cancer was determined. In the second part of the study, post-prostatic massage urine samples from 47 patients with clinically suspected prostate cancer were collected prior to prostate biopsy. The performance of PCA3 as a diagnostic aid for cancer was then assessed using the aforementioned cut-off value.
  
  
  RESULTS
  In the first part of the study, the best cut-off for the PCA3 ratio (defined as the ratio of the Ct value of PCA3/PSA mRNA) was 1.127. Applying this cut-off to the 47 patients with clinically suspected prostate cancer and no history of previous prostate biopsy, the sensitivity and specificity of PCA3 for diagnosing prostate cancer were 71% and 92%, respectively.
  
  
  CONCLUSIONS
  The post-prostatic massage urine PCA3 level shows utility for diagnosing prostate cancer in patients with elevated prostate-specific antigen levels that could facilitate decisions to undertake prostate biopsy and avoid unnecessary biopsies.
authors.affiliation: Division of Urology, Department of Surgery, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong. ngcf@surgery.cuhk.edu.hk
authors.forename: C F
authors.initials: CF
authors.lastname: Ng
authors.forename: Rachel
authors.initials: R
authors.lastname: Yeung
authors.forename: Peter K F
authors.initials: PK
authors.lastname: Chiu
authors.forename: N Y
authors.initials: NY
authors.lastname: Lam
authors.forename: Joseph
authors.initials: J
authors.lastname: Chow
authors.forename: Billy
authors.initials: B
authors.lastname: Chan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000652:urine*; D016022:Case-Control Studies; D002681:China / Q000208:ethnology; D003430:Cross-Sectional Studies; D051517:Digital Rectal Examination; D006723:Hong Kong; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012333:RNA, Messenger / Q000378:metabolism*; D012680:Sensitivity and Specificity
chemical_list: D000951:Antigens, Neoplasm; D012333:RNA, Messenger; C479341:prostate cancer antigen 3, human; D017430:Prostate-Specific Antigen