p53 in noncancerous bladder mucosa as a marker of disease recurrence in patients with superficial transitional cell carcinoma of the bladder

We investigated the prevalence and clinical relevance of p53 nuclear overexpression in histologically benign bladder mucosa in patients with superficial transitional cell cancer (TCC) of the bladder to look for “premalignant” lesions as the source of tumor recurrence. p53 Accumulation in representative tumor and normal-looking bladder mucosa was studied in 53 patients with Ta and T1 TCC. Histologically normal bladder specimens from 20 prostate cancer patients served as controls. We used a biotin streptavidine-peroxidase system to stain deparaffinized tissue sections with the p53 monoclonal antibody DO7. Specimens from 42 (79%) of the 53 TCC patients stained for p53 in the tumor area. There was no statistically significant difference between pTa and pT1 lesions (pTa, 71.4%; pT1, 87.5%), and staining correlated weakly with tumor grade (G1, 62%; G2, 82%; G3, 100%). Evaluation of histologically normal bladder mucosa showed positive p53 staining in 13 (24.5%) of the 53 patients. Disease recurred in 20 patients. Among them, 12 had positive staining in the normal bladder mucosa. Although p53 expression in tumor areas showed only slight correlation with tumor recurrence (p = 0.043, Cochran-Armitage test), p53 accumulation in healthy bladder mucosa correlated strongly with disease recurrence (p < 0.0001, Fisher’s exact test). p53 Overexpression in histologically normal bladder mucosa in patients with TCC might identify premalignant alterations in tumor-surrounding areas. Our data suggest that p53 accumulation in histologically benign bladder mucosa of TCC patients is a possible marker of disease recurrence.