title: External Evaluation of a Novel Prostate Cancer Risk Calculator (ProstateCheck) Based on Data from the Swiss Arm of the ERSPC.
abstract: We externally validated a novel prostate cancer risk calculator based on data from the Swiss arm of the ERSPC and assessed whether the risk calculator (ProstateCheck) is superior to the PCPT-RC and SWOP-RC in an independent Swiss cohort.
  
  
  
  Data from all men who underwent prostate biopsy at an academic tertiary care center between 2004 and 2012 were retrospectively analyzed. The probability of having any prostate cancer or high grade prostate cancer (Gleason score 7 or greater) on prostate biopsy was calculated using the ProstateCheck. Risk calculator performance was assessed using calibration and discrimination, and additionally compared with the PCPT-RC and SWOP-RC by decision curve analyses.
  
  
  
  Of 1,615 men 401 (25%) were diagnosed with any prostate cancer and 196 (12%) with high grade prostate cancer. Our analyses of the ProstateCheck-RC revealed good calibration in the low risk range (0 to 0.4) and moderate overestimation in the higher risk range (0.4 to 1) for any and high grade prostate cancer. The AUC for the discrimination of any prostate cancer and high grade prostate cancer was 0.69 and 0.72, respectively, which was slightly but significantly higher compared to the PCPT-RC (0.66 and 0.69, respectively) and SWOP-RC (0.64 and 0.70, respectively). Decision analysis, taking into account the harms of transrectal ultrasound measurement of prostate volume, showed little benefit for ProstateCheck-RC, with properties inferior to those of the PCPT-RC and SWOP-RC.
  
  
  
  Our independent external evaluation revealed moderate performance of the ProstateCheck-RC. Its clinical benefit is limited, and inferior to that of the PCPT-RC and SWOP-RC.
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.
authors.forename: Cédric
authors.initials: C
authors.lastname: Poyet
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.
authors.forename: Marian S
authors.initials: MS
authors.lastname: Wettstein
authors.affiliation: Department of Urology, Mater Misericordiae University Hospital, Dublin, Ireland.
authors.forename: Dara J
authors.initials: DJ
authors.lastname: Lundon
authors.affiliation: Department of Surgery, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Bimal
authors.initials: B
authors.lastname: Bhindi
authors.affiliation: Department of Surgery, Division of Urology, University Health Network, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Girish S
authors.initials: GS
authors.lastname: Kulkarni
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.
authors.forename: Karim
authors.initials: K
authors.lastname: Saba
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Zürich, Switzerland.
authors.forename: Tullio
authors.initials: T
authors.lastname: Sulser
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: A J
authors.initials: AJ
authors.lastname: Vickers
authors.affiliation: Department of Urology, University Hospital Zürich, University of Zürich, Zürich, Switzerland. Electronic address: thomas.hermanns@usz.ch.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hermanns
mesh_terms: D000368:Aged; D001706:Biopsy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000453:epidemiology* / Q000473:pathology; D012189:Retrospective Studies; D018570:Risk Assessment; D013557:Switzerland
keywords: biopsy; decision support techniques; nomograms; prostate-specific antigen; prostatic neoplasms