Reduced E-cadherin and α-catenin expressions have no prognostic role in bladder carcinoma

In various human cancers, dysfunction of the E-cadherin-catenin complex is associated with a decrease in cellular and tissue differentiation, and with higher invasive and metastatic potentials. The objective of this study was to investigate E-cadherin and alpha-catenin expression in superficial noninvasive papillary TCC and invasive TCC, and correlate these results with pathological and clinical parameters. We have used immunohistochemistry to localize E-cadherin and alpha-catenin in 56 formalin- fixed, paraffin-embedded tissue blocks from 41 patients with superficial bladder cancer and 15 with invasive bladder cancer. The 46 male and 10 female patients had a mean age of 67 years, with range of 40 to 82 years. The mean follow-up time was 33.4 ( range 5-120) months. Tumor grade 1: 2: 3 ratios were 5: 32: 19. In superficial bladder tumor, abnormal expression of E-cadherin and alpha-catenin was demonstrated in 37 and 71% of the tumors, respectively. In advanced bladder tumor, abnormal expression of E-cadherin and alpha-catenin was demonstrated in 80 and 100% of the tumors, respectively. Differences in expression of E-cadherin and alpha-catenin could be discerned between superficial and advanced bladder tumors (p= 0.004, p= 0.024, respectively). However, the association between E-cadherin and alpha-catenin expression and tumor grade was not statistically significant (p> 0.05). In addition, the expression of E-cadherin and alpha-catenin did not correlate with tumor number and size ( p> 0.05). We have demonstrated that abnormal expression of E-cadherin and/or alpha-catenin occurs in more than 85% of bladder carcinomas and correlates significantly only with advanced stage. Nevertheless, these observations need to be confirmed in larger prospective clinical studies.