Molecular characteristics of transitional cell carcinoma in childhood

Transitional cell carcinoma of the bladder is rare in children and young adults with age below 30. The risk of recurrence or progression in these patients has been shown to be low. We analyzed specific cytogenetic characteristics of transitional cell carcinomas from children and young adults as well as the p53 status of these tumors by immunohistochemistry. Seventeen patients diagnosed with transitional cell carcinoma of the urinary bladder before the age of 30 years underwent transurethral resection. Formalin-fixed, paraffin-embedded tumor specimens were sectioned and assay by in situ hybridization with centromeric probes to chromosomes 17 and y. In addition, immunohistochemistry staining for the p53 tumor suppressor gene product was performed. Four of 17 patients demonstrated aneuploidy of chromosome 17. Three of six patient demonstrated aneuploidy of chromosome y. Eleven of 17 tumors had nuclear accumulation of p53 gene product consistent with p53 gene mutation. previous investigators have hypothesized that bladder carcinomas in childhood are biologically different than tumors that occur later in life, our data suggest that mutation of p53 tumor suppressor gene is relatively common among patients with bladder carcinomas occurring before the age of 30. Aneuploidy of chromosome y and 17 is rare in childhood bladder cancer. These data support the notion that superficial transitional carcinoma occurring in young adults may have different molecular antecedents than occurring in the adult population.