title: Diagnostic Role of Serum Free-to-Total Prostate Specific Antigen (PSA) Ratio in Prostate Cancer with Serum Total Concentration of PSA below 4 ng/mL.
abstract: OBJECTIVE
  To examine the effectiveness of serum free-to-total prostate specific antigen ratio (%fPSA) for the detection of prostate cancer (PCa) in men with different serum total PSA (tPSA) categories.
  
  
  METHODS
  From January 2010 to December 2013, a total of 225 patients with lower urinary tract symptoms (LUTS) underwent tPSA and %fPSA measurements. Histological examination with calculation of Gleason score and whole body bone scans were performed in identified cases of PCa.
  
  
  RESULTS
  PCa was diagnosed in 44 (19.6%) patients and the remaining 181 patients had benign prostate disease. PCa was detected in 5 (23.8%), 13 (8.7%) and 26 (47.3%) cases with tPSA level ranges≤4 ng/ml, 4 to 10 ng/ml and >10 ng/ml, respectively. The average Gleason score was 7.2±0.2. Some 6 (13.6%) out of 44 PCa patients had bone metastases. The sensitivity was 80% and specificity was 81.3% at the cut-off %fPSA of 15% in PCa patients with a tPSA level below 4 ng/ mL. A lower %fPSA was associated with PCa patients with Gleason score≥7 than those with Gleason score≤6 (11.7±0.98 vs. 16.5±2.25%, P=0.029). No obvious relation of %fPSA to the incidence of bone metastasis was apparent in this study.
  
  
  CONCLUSIONS
  The clinical application of %fPSA could help to discriminate PCa from benign prostate disease in men with a tPSA concentration below 4 ng/mL.
authors.affiliation: Department of Clinical Pathology, Far Eastern Memorial Hospital, New Taipei, Taiwan E-mail : jacpha@mail.femh.org.tw.
authors.forename: Chih-Chun
authors.initials: CC
authors.lastname: Chang
authors.forename: Yi-Chen
authors.initials: YC
authors.lastname: Lee
authors.forename: Huang-Wen
authors.initials: HW
authors.lastname: Tsai
authors.forename: Shyi-Chun
authors.initials: SC
authors.lastname: Yii
authors.forename: Tzung-Hai
authors.initials: TH
authors.lastname: Yen
authors.forename: Fang-Yeh
authors.initials: FY
authors.lastname: Chu
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D001859:Bone Neoplasms / Q000097:blood / Q000556:secondary*; D005500:Follow-Up Studies; D006801:Humans; D007159:Immunologic Tests; D008297:Male; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000097:blood / Q000473:pathology*; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology*; D012372:ROC Curve
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen