[866] Can Quantitation and Sub-Categorization of Extraprostatic Extension (EPE) Predict Biochemical Recurrence (BCR)

Juan C Gomez-Gelvez, Mireya Diaz-Insua, Mani Menon, Nilesh Gupta. Henry Ford Hospital, Detroit

Background: EPE is defined as extension of tumor in to the periprostatic soft tissue. Prostatic capsular morphology is complex and varies from region to region. Pathologists use several different histologic criteria to diagnose EPE, but not all cases of EPE show progression of the disease. We aimed to quantify and assess the association of various EPE histologic features and BCR.
Design: Specimens from a matched cohort of 101 robotic-assisted radical prostatectomies with pT3aN0M0 performed between 2005-2008 at our institution were reviewed. EPE location, number of EPE foci, GS of EPE focus, radial extension (RE) and circumferential extension (CE) of EPE were noted. EPE was classified into three broad histologic categories (HC): 1. Tumor within adipose tissue (AT) or in fibroconnective tissue (FCT) at the level of AT (FAT) 2. Tumor in FCT beyond the prostatic muscular stroma but still not at the level of AT (FC) 3. Tumor beyond the normal contours of the prostate gland (BOC) in anterior region, base and bladder neck but not FAT or FC. Statistical significance of associations with BCR was assessed with conditional logistic regression.
Results: BCR was seen in 23 cases with 78 corresponding controls without BCR after a median follow up of 29 months. In univariate analysis, GS of EPE and RE with 1mm cutoff, were significantly (p-value<0.05) associated with BCR while CE classified into tertiles (4 and 10mm cutoff), and HC of EPE were marginally associated. Majority of BCR cases belonged to FAT (21 cases) and only 1 case of BCR was seen in FC.

EPE categoryBCRNo BCR
FAT21/79 (26.6)58/79 (73.4)
BOC1/4 (25.0)3/4 (75.0)
FC1/18 (5.6)17/18 (94.4)


In a multivariable model, only RE remained an independent predictor of BCR (OR=8.37, 1.74-40.12). An interaction between GS of EPE and RE was also found predictive with low or high GS of EPE and RE within 1mm (group 1, BCR 11/76=14.5%) and high GS of EPE and RE beyond 1mm (group 2, BCR 12/25=48%; OR=5.46, 1.98-15.00). Corresponding Kaplan-Meier graph is shown below.


Conclusions: Combination of GS of EPE focus and RE may identify risk of BCR among patients with EPE. More samples are required to define more clearly the role of CE and HC of EPE on BCR.
Category: Genitourinary (including renal tumors)

Monday, March 19, 2012 11:45 AM

Platform Session: Section A, Monday Morning

 

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