E-Cadherin, Snail and Slug Expression in a Series of Non-Muscle Invasive Bladder Carcinomas with Long-Term Follow up
Raffaella Santi, Tommaso Cai, Monica Pepi, Milena Paglierani, Riccardo Bartoletti, Gabriella Nesi. University of Florence, Florence, Italy; Santa Chiara Hospital, Trento, Italy
Background: Pathologic grading according to the 2004 WHO/ISUP proposal has been regarded as a useful tool to classify urothelial tumors into prognostically distinct categories. Unraveling molecular pathways of development for bladder carcinomas may further improve classification results. Previous reports have investigated the relationship between the expression of Snail and Slug transcription repressors and clinicopathologic features of non-muscle invasive bladder cancers.
Design: The study population consisted of 43 patients (38 men and 5 women, mean age 67.4 years), receiving transurethral resection for non-muscle invasive urothelial carcinoma. Histologic slides were reviewed and tumors were classified according to the 2004 WHO/ISUP system. Immunostaining for E-cadherin, Snail and Slug proteins was performed in all cases, and both staining intensity and percentage of positive cells were recorded. Grades according to the intensity of staining included 0, 1+, 2+, and 3+ while the percentage of positive cells was separated into 0 (0%), 1 (1% to 33%), 2 (34 to 66%), and 3 (67 to 100%). Staining results were then classified into 2 groups: weak staining (any intensity with percent category 0-1) and strong staining (intensity 2-3 with percent category 2-3).
Results: High-grade (HG) carcinomas were 21/43, with nine invasive cases (pT1). Low-grade (LG) carcinomas were 22/43, with no invasive cases (pTa). The mean follow-up period was 113.3 months. Among the 9 HGpTa cases with recurrence, strong Snail expression was detected in 7 (77.9%). Out of the 16 LGpTa patients who experienced recurrence, 11 (68.7%) showed strong positivity for Snail. Among the 9 HGpT1 cases, recurrence was observed in 4 cases and 3 (75%) of these intensely stained for Snail. With regard to immunohistochemical Snail status, Kaplan-Meier analysis demonstrated significantly different recurrence rates between patients with strong reactivity and those with weak reactivity (p= 0.003). E-cadherin and Slug expression did not correlate with any of the clinicopathologic parameters considered.
Conclusions: Overexpression of Snail may represent a clinically relevant mechanism of cancer progression in bladder urothelial carcinoma.
Category: Genitourinary (including renal tumors)
Wednesday, March 21, 2012 1:00 PM
Poster Session VI # 139, Wednesday Afternoon