Abstract
Objective: The purpose of this study was to evaluate the association between the p53 protein status in the sera and tumors of bladder cancer patients.
Patients and methods: We studied clinical data, i.e. age, sex, type, grade, stage, surgery and prognosis of 38 patients with carcinoma of bladder. The sera of these patients were analyzed for serum p53 protein by enzyme-linked immunosorbent assay (ELISA) and tissue p53 by immunohistochemical technique.
Results: Serum p53 antigen and tissue p53 were detected in the sera of 26 of the 38 (68.4%) and 18 of the 38 patients (47.4%), respectively. The mean serum p53 level in positive tissue p53 patients was 55.2 U/ml, which was significantly higher when compared with mean serum p53 level in negative tissue p53 patients In patients with positive tissue p53 serum p53 was positive in 17 (94.4%) patients and negative in 1 (5.5%) patient only, which was statistically insignificant. In negative tissue p53 patients (52.6%) serum p53 was negative in 11 (55%) patients and positive in 9 (45%) patients. Statistically significant correlation was observed between tissue p53 and serum p53 with type grade and stage of the tumor. Statistically significant correlation was observed between recurrence of the tumor and tissue p53 and serum p53 status Survival was estimated by the Kaplan–Meier method and log-rank test, which showed that the overall survival was better in tissue p53 and serum p53 negative patients.
Conclusion: This study shows a strong relationship between p53 protein overexpression and the occurrence of p53 in the sera of bladder cancer patients. The expression of p53 in sera 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. Further studies to elucidate the mechanism of p53 migration into the sera will be necessary for a better understanding of the immune status in bladder cancer patients.