title: Biopsy diagnosis of intraductal carcinoma is prognostic in intermediate and high risk prostate cancer patients treated by radiotherapy.
abstract: OBJECTIVE
  We investigated the prognostic significance of intraductal carcinoma of the prostate (IDC-P) in biopsies and transurethral resections prior to external beam radiotherapy with or without androgen deprivation.
  
  
  METHODS
  Cohort 1 consisted of 118 intermediate risk prostate cancer patients treated by radiotherapy, with biochemical relapse as primary end-point (median follow-up 6.5 years). Cohort 2 consisted of 132 high risk patients, enrolled in a phase III randomised trial (EORTC 22863) comparing radiotherapy alone to radiotherapy with long-term androgen deprivation (LTAD) with clinical progression free survival as primary end-point (median follow-up 9.1 years). Presence of IDC-P was identified after central review. Multivariable regression modelling and Kaplan-Meier analysis were performed with IDC-P as dichotomous variable.
  
  
  RESULTS
  IDC-P was a strong prognosticator for early (<36 months) biochemical relapse (HR 7.3; p = 0.007) in cohort 1 and for clinical disease-free survival in both arms of cohort 2 (radiotherapy arm: HR 3.5; p < 0.0001; radiotherapy plus LTAD arm: HR 2.8, p = 0.018). IDC-P retained significance after stratification for reviewed Gleason score in the radiotherapy arm (HR 2.3; p = 0.03). IDC-P was a strong prognosticator for metastatic failure rate (radiotherapy arm: HR 5.3; p < 0.0001; radiotherapy plus LTAD arm: HR 3.6; p = 0.05).
  
  
  CONCLUSIONS
  IDC-P in diagnostic samples of patients with intermediate or high risk prostate cancer is an independent prognosticator of early biochemical relapse and metastatic failure rate after radiotherapy. We suggest that the presence of IDC-P in prostate biopsies should routinely be reported.
authors.affiliation: Dept of Pathology, University Health Network, Toronto, Canada. theo.vdkwast@uhn.on.ca
authors.forename: T
authors.initials: T
authors.lastname: Van der Kwast
authors.forename: N
authors.initials: N
authors.lastname: Al Daoud
authors.forename: L
authors.initials: L
authors.lastname: Collette
authors.forename: J
authors.initials: J
authors.lastname: Sykes
authors.forename: J
authors.initials: J
authors.lastname: Thoms
authors.forename: M
authors.initials: M
authors.lastname: Milosevic
authors.forename: R G
authors.initials: RG
authors.lastname: Bristow
authors.forename: G
authors.initials: G
authors.lastname: Van Tienhoven
authors.forename: P
authors.initials: P
authors.lastname: Warde
authors.forename: R-O
authors.initials: RO
authors.lastname: Mirimanoff
authors.forename: M
authors.initials: M
authors.lastname: Bolla
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000175:diagnosis* / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D015331:Cohort Studies; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D012307:Risk Factors; D016896:Treatment Outcome