[848] Incidental Prostate Pathology in Cytoprostatectomy Specimens: Is Partial Prostate Sampling Adequate?

Emily Filter, Manal Y Gabril, Jose A Gomez, Peter Wang, Jonathan Izawa, Joseph Chin, Madeleine Moussa. London Health Sciences Centre, London, ON, Canada

Background: The standard treatment for muscle-invasive bladder cancer is radical cystoprostatectomy (RCP). The reported rate of incidentally detected prostate adenocarcinoma (Pca) in RCP varies from 14% to 54%. Overall, 25% of patients undergoing RCP harbour "clinically significant" disease despite a normal preoperative prostate exam. The wide variability in incidental Pca detection may be explained by different institutional grossing protocols. The aim of our study is to evaluate the incidence, pathologic features and clinical significance of incidental Pca in RCP specimens with partial versus complete prostate submission.
Design: 158 RCP performed for invasive bladder cancer between 1990 and 2006 in our institution were reviewed. No cases had previous history of Pca. Pathological features of Pca (Gleason score, margin status, extraprostatic extension, seminal vesicle invasion, lymphovascular invasion, and tumor focality) were assessed and correlated with clinical data (PSA, distant metastasis and survival). Two approaches of sampling were compared in our institution: partial versus complete prostate submission.
Results: 158 RCP cases were reviewed. 59 (37.3%) and 99 (62.7%) cases represented partial and complete prostate sampling respectively. Incidental Pca was detected in 72/158 (45.5%) in which Gleason score was ≥ 7 in 31.9% of cases. 17/72 (23.6%) and 55/72 (76.4%) with incidental Pca were cases with patrial and complete sampling of the gland respectively.

Table 1: Focality of Pca in Partial vs. Complete Prostate Submission

Pca Incidence	Partial (n=17/72)( 23.6%)	Complete (n=55/72)(76.4%)
Unifocal (33/72) (45.8%)	8/33 (24.2%)	25/33 (75.8%)
Multifocal (39/72)(54.1%)	9/39 (23.1%)	30/39 (76.9%)

The overall rate of concomitant Pca and invasive and/or in situ urothelial carcinoma (CIS) of the prostate was 29.1% (21/72). Both types of cancers were identified in 13/21 (61.9%) of RCP cases with microscopic examination of the entire prostate compared to 8/21 (38.1%) of cases with partial submission. 6/21 cases (28.6%) contained both Pca and CIS involving prostatic urethra. Of these 6 cases, 4 (66.7%) were detected with complete prostate evaluation.
Conclusions: Our findings suggest that complete evaluation of the prostate in RCP specimens yields higher detection rates of both incidental Pca and involvement by invasive and/or in situ urothelial carcinoma. Although there is currently no internationally accepted protocol for prostate sampling in cases of RCP, our data support consideration of this approach.
Category: Genitourinary (including renal tumors)

Tuesday, March 20, 2012 1:00 PM

Poster Session IV # 116, Tuesday Afternoon