Objective: Mutations in the p53 gene are frequently detected in some types of malignant tumors (bladder, prostate, kidney, lung, breast, colon and rectum). This study analyzed the utility of p53 quantitation in transitional cell carcinoma of the bladder and evaluated the results at 5 years.
Methods: A prospective clinical cohort study was conducted on 81 patients. The study comprised two groups: nontumoral bladder tissue specimens from 20 patients (group I) and tissue specimens from 61 patients with bladder carcinoma (group II). In both groups the tissue specimens were obtained between November 1992 and November 1993, including the follow-up period until July 1998. p53 expression was determined by a quantitative method based on immunoluminiscence (LIA-MAT p53).
Results: p53 expression was higher in bladder carcinoma than in healthy urothelial tissue; higher values of p53 were found for infiltrating and undifferentiated tumors. The p53 values were higher in patients with tumor recurrence than in those without (NS). The Bonferroni multiple comparisons test showed a higher mortality in patients with p53 > 0.9 than in patients who are alive or have died from other causes (p = 0.000).
Conclusion: The results show that p53 LIA-MAT is an independent prognostic factor at a cutoff of 0.9 and permits identification of a subgroup of patients at high risk.