title: Clinical utility of prostate-specific antigen mass ratio for prediction of prostate cancer detection on a repeated prostate biopsy.
abstract: OBJECTIVE
  To assess the clinical utility of the prostate-specific antigen mass ratio (PSA- MR), a newly developed PSA derivative, simply defined as the (i) PSA density (PSA-D) multiplied by the plasma volume or (ii) total PSA amount in circulation per prostate volume, for predicting prostate cancer (PCa) among men undergoing repeated prostate biopsy (PBx).
  
  
  METHODS
  Patients (n = 286), who underwent a repeated PBx, were analyzed. The various parameters associated with PCa detection were noted in each patient. PSA-MR was also calculated.
  
  
  RESULTS
  PCa was detected in 63 (22.0%) of 286 patients. PSA-MR was the independent predictor in the univariate- and multivariate logistic regression analyses (OR = 3.448, p = 0.001 and OR = 13.430, p = 0.033, respectively). A nomogram that incorporated PSA-MR was considered a useful tool (predictive accuracy: 79.2%, 95% CI: 0.726-0.858, p < 0.001). Furthermore, a nomogram that incorporated PSA-MR would have avoided 59.6% of unnecessary repeated PBx. The predictive accuracy of PSA-MR was also superior to that of PSA or PSA-D (p = 0.013 and 0.009, respectively).
  
  
  CONCLUSIONS
  PSA-MR was an independent predictor, and its consideration would have avoided 59.6% of unnecessary repeated PBx for PCa detection. PSA-MR was also superior than PSA or PSA-D. Our results support the use of PSA-MR to facilitate counseling with patients after a negative initial PBx, and use of PSA-MR might reduce further unnecessary biopsies.
authors.affiliation: Department of Urology, Hallym University Chuncheon Sacred Heart Hospital, Chuncheon, Korea.
authors.forename: Won Ki
authors.initials: WK
authors.lastname: Lee
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sangchul
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Hong
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Lee
authors.affiliation: Department of Urology, Choi Won Suk Urology Clinic, Yongin, Korea.
authors.forename: Won Suk
authors.initials: WS
authors.lastname: Choi
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Seok-Soo
authors.initials: SS
authors.lastname: Byun
mesh_terms: D000368:Aged; D001706:Biopsy; D015992:Body Mass Index; D051517:Digital Rectal Examination; D006801:Humans; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000473:pathology*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D013997:Time Factors
chemical_list: D017430:Prostate-Specific Antigen