[818] E-Cadherin Expression in Prostatic Adenocarcinoma: Correlation with Gleason Score and Comparison with Invasive High Grade Urothelial Carcinoma

Elizabeth C Chastain, Sarfraz Ali, Adeboye O Osunkoya. Emory University School of Medicine, Atlanta

Background: Alteration of expression of the cellular adhesion molecule E-cadherin has been linked to invasive phenotypes of a variety of neoplasms. Hitherto, there have been limited studies of E-cadherin expression in prostatic adenocarcinoma (PCa). The utility of E-cadherin in the distinction between PCa and urothelial carcinoma (UCa) has also not been well characterized. The goals of this study are; (a) to determine E-cadherin expression in PCa, with emphasis on correlation with Gleason score, and (b) to determine if it can be included in the panel of markers to distinguish between PCa and UCa.
Design: A search through the surgical pathology and consultation files of a large academic institution was made for cases of PCa with Gleason scores 6, 7, 8 and 9. 10 cases of usual type invasive high grade UCa were also included in the study. To exclude the possibility of variability of marker expression, TMA analysis was not utilized. All cases were obtained from representative slides of radical prostatectomy, cystectomy, transurethral resection, or needle core biopsy specimens. Slides were stained with antibodies to E-cadherin and examined for degree of expression (Negative: 0, weak: 1+, moderate: 2+ and strong: 3+).
Results: 81 cases of PCa were identified with Gleason scores as follows; 23 cases (Gleason score 3+3=6), 25 cases (Gleason score 3+4=7 or 4+3=7), 17 cases (Gleason score 4+4=8), and 16 cases (Gleason score 4+5=9). 65 cases (80%) of PCa had moderate to strong (2+ to 3+) E-cadherin expression and only 16 cases (20%) showed negative or weak (1+) E-cadherin expression. Moderate to strong (2+ to 3+) E-cadherin expression was observed in 20/23 cases (87%) of Gleason score 3+3=6, 22/25 cases (88%) of Gleason score 3+4=7 or 4+3=7, 11/17 cases (65%) of Gleason score 4+4=8 and 12/16 cases (75%) of Gleason score 4+5=9. Of the 16 cases with negative or weak (1+) E-cadherin expression, 3/23 cases (13%) were Gleason score 3+3=6, 3/25 (12%) were Gleason score 3+4=7 or 4+3=7, 6/17 cases (35%) were Gleason score 4+4=8, and 4/16 cases (25%) were Gleason score 4+5=9. 10/10 cases (100%) of usual type invasive high grade UCa had moderate to strong (2+ to 3+) E-cadherin expression.
Conclusions: E-cadherin expression in PCa is not consistently decreased with increased Gleason score, and thus may not be involved in differentiation of PCa. The expression of E-cadherin in PCa, Gleason scores 4+4=8 and 4+5=9, also precludes this marker from being used in a panel to distinguish between high grade PCa and usual type invasive high grade UCa.
Category: Genitourinary (including renal tumors)

Wednesday, March 21, 2012 9:30 AM

Poster Session V # 127, Wednesday Morning

 

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