title: Value of prostate-specific antigen (PSA) mass ratio in the detection of prostate cancer in men with PSA levels of ≤10 ng/mL.
abstract: A group of researchers introduced a parameter named PSA mass ratio, which is defined as total circulating PSA protein (PSA [ng/mL] x plasma volume [L]) per prostate volume, as a prostate cancer screening tool. They suggested that PSA mass ratio may be representative of a PSA value adjusted for potentially influencing factors, such as haemodilution and prostate volume. By adjusting for the combined effects of plasma volume and prostate volume, it can be hypothesized that PSA mass ratio would enhance the predictive value of the PSA test. Although PSA mass ratio appears to be an attractive alternative to serum PSA level, PSA mass ratio may not significantly enhance the currently available method to predict prostate cancer detection among men with PSA level of ≤10 ng/mL who are undergoing prostate biopsy.
  
  
  OBJECTIVE
  To investigate the value of prostate-specific antigen (PSA) mass ratio, defined as total PSA in circulation per prostate volume (PV), in the prediction of prostate cancer detection among men with PSA levels of ≤10 ng/mL who are undergoing prostate biopsy.
  
  
  METHODS
  We reviewed records of 2431 men aged 56-80 years who presented with PSA levels of ≤10 ng/mL and underwent multi (≥12)-core transrectal ultrasound-guided prostate biopsy at our institution. Predictive accuracies of relevant variables and multivariate models in the prostate cancer detection via biopsy were assessed with receiver operating characteristics-derived area under the curve and compared.
  
  
  RESULTS
  When compared one-on-one, PSA mass ratio had a significantly higher accuracy than PSA in the prediction of prostate cancer among our subjects (0.638 vs 0.565, P < 0.001). Meanwhile, when multivariable model for the prediction of prostate cancer detection via prostate biopsy was devised incorporating patient age, body mass index, digital rectal examination findings, PV, number of biopsy cores, and PSA level, the replacement of PSA level with PSA mass ratio (P = 0.102) or the addition of PSA mass ratio (P = 0.164) in the model was not associated with significantly increased accuracy of model for predicting prostate cancer detection via biopsy.
  
  
  CONCLUSIONS
  Although PSA mass ratio appears to be an attractive alternative to PSA level, PSA mass ratio may not significantly enhance the currently available method to predict prostate cancer detection among men with PSA levels of ≤10 ng/mL who are undergoing prostate biopsy.
authors.affiliation: Department of Urology, Seoul National University Bundang Hospital, Seongnam, Korea.
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Hong
authors.forename: Jong Jin
authors.initials: JJ
authors.lastname: Oh
authors.forename: Seok-Soo
authors.initials: SS
authors.lastname: Byun
authors.forename: Sung Il
authors.initials: SI
authors.lastname: Hwang
authors.forename: Min Soo
authors.initials: MS
authors.lastname: Choo
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Lee
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D015992:Body Mass Index; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000473:pathology*; D012372:ROC Curve; D012189:Retrospective Studies; D047368:Tumor Burden; D018084:Ultrasonography, Interventional
chemical_list: D017430:Prostate-Specific Antigen