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 sectio ns of 111 bladder tumours and 13 normal bladder specimens by means of immun ohistochemistry, 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 a bnormal 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 signific ant 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 quantific ation differed significantly for low and high expression (log-rank test: P= 0.0006). These results suggest that the alteration occurs at the transcript ional level and support the clinical and biological relevance of cell adhes ion molecules in bladder cancer. (C) 2000 Cancer Research Campaign.