title: A risk-based strategy improves prostate-specific antigen-driven detection of prostate cancer.
abstract: BACKGROUND
  Screening for prostate cancer (PC) is controversial due to uncertainties about its efficiency.
  
  
  OBJECTIVE
  We aimed to develop strategies to reduce the number of unnecessary biopsies while still detecting most clinically important PC cases.
  
  
  METHODS
  In 1850 men initially screened and biopsied (prostate-specific antigen [PSA] value > or =3.0 ng/ml) in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer, we calculated both the probability of having a positive lateralized sextant biopsy [P(biop+)] and the probability of having an indolent cancer [P(ind)] if PC was detected at biopsy (n=541). Analyses of repeat screening included 225 cancers in 1201 men.
  
  
  METHODS
  The P(biop+) was based on applying a logistic regression model that included ultrasound volume, digital rectal exam, and transrectal ultrasound in addition to the PSA value. The P(ind) was based on a recently validated nomogram. MEASUREMENTS AND LIMITATIONS: At initial screening the fraction of positive biopsies was 29% (541 of 1850). Applying an additional P(biop+) cut-off of 12.5% implied that 613 of the 1850 men (33%) would not have been biopsied. This would result in an increase in the positive predictive value (PPV) to 38% (468 of 1237). At repeat screening a similar P(biop+) cut-off would result in an increase in the PPV from 19% (225 of 1201) to 25% (188 of 760). Thirteen percent of PC cases would not have been diagnosed, of which 70% (initial screening) and 81% (repeat screening) could be considered as potentially indolent. None of the deadly PC cases would have been missed. A PSA cut-off of > or =4.0 ng/ml resulted in similar numbers of biopsied cases saved but considerably higher numbers of missed diagnoses.
  
  
  CONCLUSIONS
  An individualized screening algorithm using other available prebiopsy information in addition to PSA level can result in a considerable reduction of unnecessary biopsies. Very few important PC cases, for which diagnosis at a subsequent screening visit might be too late for treatment with curative intent, would be missed.
authors.affiliation: Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands. m.roobol@erasmusmc.nl
authors.forename: Monique J
authors.initials: MJ
authors.lastname: Roobol
authors.forename: Ewout W
authors.initials: EW
authors.lastname: Steyerberg
authors.forename: Ries
authors.initials: R
authors.lastname: Kranse
authors.forename: Tineke
authors.initials: T
authors.lastname: Wolters
authors.forename: Roderick C N
authors.initials: RC
authors.lastname: van den Bergh
authors.forename: Chris H
authors.initials: CH
authors.lastname: Bangma
authors.forename: Fritz H
authors.initials: FH
authors.lastname: Schröder
mesh_terms: D000465:Algorithms; D001706:Biopsy; D051517:Digital Rectal Examination; D006305:Health Status Indicators; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods*; D009426:Netherlands; D049451:Nomograms; D011237:Predictive Value of Tests; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D014463:Ultrasonography; D019564:Unnecessary Procedures
chemical_list: D017430:Prostate-Specific Antigen