The correlation of p53 protein overexpression and p53 antibodies in serum of patients with transitional cell carcinoma of the urinary bladder

Background: Mutations of p53 gene were demonstrated in many solid tumors with varying frequency. We analyzed the relationship between p53 protein expression in bladder cancer tissue, p53 autoantibodies in serum and the clinical course of 32 patients with and 10 patients without transitional cell carcinoma of the urinary bladder.

Materials and methods: In the 32 patients studied, bladder cancer was diagnosed as pTaG1-2 in 8 cases, pT1G2 in 6, pT1G3 in 7, pT2G2-3 in 7, pT3G2-3 in 3 and pT4 in 1 patient. Anti-p53 antibodies were detected by an enzyme-linked immunosorbent assay. Immunohistochemical staining was performed using a standardized alkaline phosphatase monoclonal anti-alkaline phosphatase method. To prove the statistical significance of tumor grading and staging, the Kruskal-Wallis test was applied (p < 0.01). The mean follow-up was 26 months.

Results: We found 12.5% p53 autoantibody-positive sera without a statistically significant correlation with tumor grade (p = 0.0569) and category (p = 0.612). Three of 4 patients who had p53 autoantibody-positive sera died within 9 months. All of these sera-positive patients had p53 protein-positive tumor tissue. Control sera were all negative for p53 autoantibodies.

Conclusion: This study shows a strong relationship between p53 protein overexpression and the occurrence of p53 autoantibody in bladder cancer. The expression of p53 autoantibodies seems to be an event in cases of bladder cancer with an unfavorable tumor-specific outcome. Because of the small number of cases and the short follow-up time, further quantitative studies will hopefully demonstrate whether this might be of prognostic importance.