Cripto-1 is a tumour specific marker of bladder cancer

The recently identified epidermal growth factor related peptide cripto-1 has been previously implicated in the development of the malignant phenotype The immunohistochemical identification of gene products that can act as prognostic markers in bladder cancer would be of value in determining management of this heterogeneous group of patients. The expression of cripto-1 protein in benign and malignant bladder was therefore examined Forty five bladder tumours (Ta/Tl n =26, T2 n = 5, T3/T4 n = 14) and 6 benign controls (2 normal bladder, 2 benign prostatic hyperplasia and 2 cystitis), were stained for cripto-1 using immunohistochemical techniques. All 45 tumours stained positively for cripto-1. Of these tumours all stained positively for cripto-1 in adjacent histologically normal bladder tissue when present. None of the 6 benign controls had positive cripto-1 staining. Twenty three (60%) bladder tumours showed strong positive staining for cripto-1 compared to 6 (29%) sections of histologically normal bladder adjacent to tumour (p <0.05). There was no association between cripto-1 staining and tumour grade, stage or clinical outcome. In conclusion, this study suggests that cripto-1 protein may be involved in the development of the malignant phenotype in human urothelium. Cripto-l is specifically expressed in malignant and adjacent benign urothelium of patients with bladder cancer. Its clinical significance however, remains to be determined.