Abnormalities in p53 and DNA content in transitional cell carcinoma of the bladder

Objective To determine if transitional cell tumours of the bladder which contain mutations in the p53 gene have alterations in their DNA content. Materials and methods In 33 transitional cell tumours of the bladder, DNA content was determined by flow cytometry and compared with expression of mutant p53 as assessed by immuno‐histochemistry. Results Abnormal DNA content was associated with increased staining for p53 (P < 0.05), high tumour stage (P < 0.001) and increased histological grade (P < 0.01). Although positive staining for p53 was frequently associated with abnormal DNA content, a significant number of non‐diploid tumours stained negatively for mutant p53. Conclusion These data demonstrate that increased staining for p53 is associated with abnormalities in DNA content suggesting that mutation of the p53 gene is associated with an increased rate of chromosomal abnormalities and an increased rate of cell proliferation.