E-cadherin expression in urothelial carcinoma in situ, superficial papillary transitional cell carcinoma, and...

Flat urothelial carcinoma in situ (CIS) is a precursor of invasive transitional cell carcinoma (TCC). High-grade TCCs frequently are accompanied by CIS in surrounding urothelium. In contrast, superficial, noninvasive papillary TCCs are often low grade and generally are unaccompanied by CIS. E-cadherin (E-CD) is a member of a family of transmembrane glycoproteins involved in intercellular adhesion. Loss or decreased expression of E-CD has been linked to the invasive phenotype of a wide variety of human neoplasms, including bladder tumors. The objective of this study was to compare the expression of E-CD in high-grade urothelial dysplasia (HD)/CIS, superficial papillary TCC, benign urothelium, and invasive TCC. Staining for E-CD was performed in formalin-fixed, paraffin-embedded sections using a Ventana NexES immunostainer (Tuscon, AZ). Percentage and intensity of cell membrane staining for E-CD was calculated for the 4 groups using the quantitative Automatic Cellular Imaging System (ChromaVision, San Juan Capistrano, CA). The results were as follows: The CIS group (n = 23) had percentage and intensity (92.8%, 120.0 U) of E-CD expression similar to the superficial noninvasive papillary TCC group (n = 16, 97.8%, 123.0 U) and the benign urothelium group (n = 17, 87.9%, 104.6 U), but it had statistically significant higher percentage and intensity than the invasive TCC group (n = 15, 45.4%, and 39.2 U, P <.05). Our data indicate that CIS and superficial, noninvasive papillary TCCs strongly express E-CD. In contrast, loss of E-CD expression is associated with the invasive TCC phenotype. Only when TCCs become invasive does E-CD expression decrease in directly proportion to the depth of invasion.