title: The probability of Gleason score upgrading between biopsy and radical prostatectomy can be accurately predicted.
abstract: The objective of this study was to test the external validity of a previously developed nomogram for the prediction of Gleason score upgrading (GSU) between biopsy and radical prostatectomy (RP). The study population consisted of 973 assessable patients treated with RP at a tertiary care institution. The accuracy of the nomogram was quantified with the receiver operating characteristics curve-derived area under the curve. The performance characteristics (predicted vs observed rate of GSU) were tested within a calibration plot. Overall, GSU was recorded in 39.8% (n = 387) of patients at RP. Of patients with GSU, 70 (18.1%), 23 (5.9%) and 32 (8.3%), respectively, had extracapsular extension, seminal vesicle invasion and lymph node invasion. The accuracy of the nomogram was 74.9% (confidence interval 72.1-77.6%). The model tended to underestimate the observed rate of GSU and the discordance between the predicted and observed rate of GSU ranged from -7 to +10%. The current tool represents the most accurate method of predicting GSU between biopsy and RP. Nonetheless it is not perfect and its performance characteristics should be known prior to its use in clinical decision-making.
authors.affiliation: Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Quebec, Canada.
authors.forename: Umberto
authors.initials: U
authors.lastname: Capitanio
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.forename: Claudio
authors.initials: C
authors.lastname: Jeldres
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.forename: Andrea
authors.initials: A
authors.lastname: Gallina
authors.forename: Nazareno
authors.initials: N
authors.lastname: Suardi
authors.forename: Andrea
authors.initials: A
authors.lastname: Cestari
authors.forename: Giorgio
authors.initials: G
authors.lastname: Guazzoni
authors.forename: Andrea
authors.initials: A
authors.lastname: Salonia
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
mesh_terms: D001706:Biopsy / Q000706:statistics & numerical data; D003657:Decision Making; D006801:Humans; D008297:Male; D009367:Neoplasm Staging; D049451:Nomograms; D011237:Predictive Value of Tests; D015995:Prevalence; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery*; D015203:Reproducibility of Results; D012720:Severity of Illness Index