title: Comparison of intravesical prostatic protrusion, prostate volume and serum prostatic-specific antigen in the evaluation of bladder outlet obstruction.
abstract: OBJECTIVE
  The aims of this study were to define the relationship between intravesical prostatic protrusion (IPP), prostate-specific antigen (PSA) and prostate volume (PV) and to determine which one of them is the best predictor of bladder outlet obstruction (BOO) due to benign prostatic enlargement.
  
  
  METHODS
  A prospective study of 114 male patients older than 50 years examined between November 2001 and 2002 was performed. They were evaluated with digital rectal examination, International Prostate Symptoms Score, PSA, uroflowmetry, postvoid residual urine measurement, IPP and PV using transabdominal ultrasound scan. Statistical analysis included scatter plot with Spearman's correlation coefficients and nominal logistic regression
  
  
  RESULTS
  Prostate volume, IPP and PSA showed parallel correlation. Although all three indices had good correlation with BOO index, IPP was the best. The Spearman rho correlation coefficients were 0.314, 0.408 and 0.507 for PV, PSA and IPP, respectively. Using receiver-operator characteristic curves, the areas under the curve for PV, PSA and IPP were 0.637, 0.703 and 0.772, respectively. The positive predictive values of PV, PSA and IPP were 65%, 68% and 72%, respectively. Using a nominal regression model, IPP remained the most significant independent index to determine BOO.
  
  
  CONCLUSIONS
  All three non-invasive indices correlate with one another. The study showed that IPP is a better predictor for BOO than PSA or PV.
authors.affiliation: Department of Urology, Singapore General Hospital, Singapore.
authors.forename: Kok Bin
authors.initials: KB
authors.lastname: Lim
authors.forename: Henry
authors.initials: H
authors.lastname: Ho
authors.forename: Keong Tatt
authors.initials: KT
authors.lastname: Foo
authors.forename: Michael Yuet Chen
authors.initials: MY
authors.lastname: Wong
authors.forename: Stephanie
authors.initials: S
authors.lastname: Fook-Chong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000097:blood*; D001706:Biopsy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011467:Prostate / Q000000981:diagnostic imaging / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000097:blood / Q000150:complications / Q000473:pathology; D012720:Severity of Illness Index; D014463:Ultrasonography; D001743:Urinary Bladder / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D001748:Urinary Bladder Neck Obstruction / Q000097:blood / Q000209:etiology / Q000473:pathology; D014563:Urodynamics
chemical_list: D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen