[1040] Biopsy Diagnosis of Intraductal Carcinoma Is Prognostic in Intermediate and High Risk Prostate Cancer Patients Treated by Radiation

Theodorus H Van der Kwast, Najla Aldaoud, Laurence Collette, Jenna Sykes, Michel Bolla, Rob G Bristow. Princess Margaret Hospital, University Health Network, Toronto, Canada; Jordan University of Science and Technology, Irbid, Jordan; EORTC Headquarter, Brussels, Belgium; Grenoble University Hospital, Grenoble, France

Background: Intraductal carcinoma of the prostate (IDC-P) is associated with high grade prostate cancer. In radical prostatectomy specimens, the presence of intraductal carcinoma of the prostate is an independent prognosticator for biochemical recurrence. We investigated the frequency and prognostic significance of IDC-P in biopsies and transurethral resections of two patient cohorts prior to radiotherapy.
Design: Cohort 1 consisted of 118 patients with intermediate risk prostate cancer treated by radiotherapy, with biochemical recurrence as endpoint (median follow-up 6.5 year). Cohort 2 consisted of 132 high risk patients, enrolled in a randomized trial (EORTC 22863) comparing radiotherapy alone to radiotherapy with long-term androgen deprivation (LTAD) with clinical progression free survival as primary endpoint (median follow-up 9.1 year). The presence of IDC-P was identified after central review of the available HE-stained slides.

Multivariable regression modelling and Kaplan Meier analysis was performed with IDC-P as dichotomous variable.
Results: In this retrospective study IDC-P was identified in 19% and 22% of cohort 1 and 2 tissues, respectively. IDC-P was a strong prognosticator for early (< 36 months) biochemical recurrence (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 2.5; p=0.03). IDC-P was a strong prognosticator for metastatic disease (radiotherapy arm: HR 5.3; p< 0.0001; radiotherapy plus LTAD arm: HR 3.6; p=0.05).
Conclusions: IDC-P in diagnostic prostate samples of patients with intermediate or high risk prostate cancer is an independent prognosticator for progression free survival and metastatic disease, after radiotherapy. We suggest that the presence of IDC-P in prostate biopsies should routinely be reported.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 8:15 AM

Platform Session: Section A, Monday Morning

 

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