Low E-cadherin expression in bladder cancer at the transcriptional and protein level provides prognostic information

We studied E-cadherin down-regulation at the protein level in frozen sections of 111 bladder tumours and 13 normal bladder specimens by means of immunohistochemistry, and at the mRNA level by semi-quantitative RT-PCR in 40 of the same tumours. Results indicate that E-cadherin expression detected by immunohistochemistry correlated with both stage and grade (P < 0.0001 and P < 0.001, respectively). Analysis of recurrence, progression and survival over a mean period of 36 months after surgery in the entire cohort showed that abnormal E-cadherin immunoreactivity correlated strongly with poor outcome (log-rank test: P = 0.001, P = 0.0001 and P = 0.0003, respectively). In multistep logistic regression analysis, only E-cadherin status and stage had significant additional prognostic value (P= 0.008 and OR = 0.2; P= 0.03 and OR = 3.6, respectively). Survival estimates derived from RT-PCR transcript quantification differed significantly for low and high expression (log-rank test: P = 0.0006). These results suggest that the alteration occurs at the transcriptional level and support the clinical and biological relevance of cell adhesion molecules in bladder cancer.