title: Validation of 1997 Partin Tables' lymph node invasion predictions in men treated with radical prostatectomy in Montreal Quebec.
abstract: OBJECTIVE
  The accuracy of 1997 Partin Tables' lymph node invasion (LNI) predictions exhibits important variability in different testing populations. We explored the LNI predictive accuracy in radical prostatectomy (RP) patients from Montreal, Canada. Moreover, we assessed the extent of change in predictive accuracy related to a modification of PSA coding from categorical to continuous.
  
  
  METHODS
  We used pretreatment serum PSA, clinical stage, and biopsy Gleason sum from 537 men treated with RP to compare predicted and observed rates of LNI. Accuracy was quantified with receiver-operating characteristics curves.
  
  
  RESULTS
  Accuracy was 0.760 in 369 evaluable patients, when categorically coded pretreatment PSA (0-4, 4.1-10, 10.1-20, 20.1+) was combined with clinical stage and biopsy Gleason sum. A 2.7% accuracy increase was noted when categorically coded PSA was replaced with continuously coded values.
  
  
  CONCLUSIONS
  Partin Tables' LNI predictions showed comparable accuracy to a community-based sample from the United States (0.766), and to a recent, multi-institutional sample (0.740). However, accuracy was lower than reported in internal (0.818), and external (0.837) academic, validation cohorts. Accuracy of LNI predictions was appreciably higher, when continuously coded PSA was used.
authors.affiliation: Department of Surgery (Urology), Centre Hospitalier de l'Université de Montréal, Montréal, Québec, Canada.
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Lattouf
authors.forename: Paul
authors.initials: P
authors.lastname: Perrotte
authors.forename: Luc
authors.initials: L
authors.lastname: Valiquette
authors.forename: François
authors.initials: F
authors.lastname: Bénard
authors.forename: Michael
authors.initials: M
authors.lastname: McCormack
authors.forename: Catherine
authors.initials: C
authors.lastname: Ménard
authors.forename: Thierry
authors.initials: T
authors.lastname: Lebeau
authors.forename: Serge
authors.initials: S
authors.lastname: Benayoun
authors.forename: Alvaro
authors.initials: A
authors.lastname: Ramirez
authors.forename: Simon
authors.initials: S
authors.lastname: Ouaknine
authors.forename: Fred
authors.initials: F
authors.lastname: Saad
mesh_terms: D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D011237:Predictive Value of Tests; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D011792:Quebec; D015203:Reproducibility of Results