E-CADHERIN CELL-ADHESION MOLECULE EXPRESSION AS A DIAGNOSTIC ADJUNCT IN UROTHELIAL CYTOLOGY

E-cadherin (E-CD) is a cell-adhesion molecule that has been associated with invasion and metastasis in a wide variety of human neoplasms. We have recently shown that, although decreased E-CD expression is assoc iated with increased bladder-wall invasion and higher tumor grade of i nfiltrating transitional cell carcinomas (TCC), E-CD expression in the exophytic portion of pure papillary and papillary-infiltrating TCC is increased over that of normal transitional cells. To evaluate whether E-CD levels could serve as a diagnostic adjunct in urinary cytology s pecimens, we stained 40 alcohol-fixed bladder-washing cytospin prepara tions with an avidin-biotin-peroxidase method using a monoclonal antib ody to E-CD (Sigma Chemical Co., St. Louis, MO). E-CD expression level was defined as a high intensity or low-intensity staining increase ov er background squamous cell staining for the transitional cells in 21 biopsy-proven transitional cell carcinomas with papillary components, and in 19 benign or reactive control specimens. Twenty-one of 21 TCC ( 100%) showed an increased E-CD level over background, with 13 low-inte nsity and 8 high-intensity cases. This difference between malignant an d benign specimens was statistically significant (chi-square test, P = 0.001). We conclude that increased E-CD expression in the papillary c omponents of TCC can be identified in urinary cytology specimens, may reflect the physical and chemical structural makeup of papillary archi tecture, and warrants further study as a diagnostic adjunct in the int erpretation of urine cytology specimens. (C) 1996 Wiley-Liss, Inc.