Objective: To investigate the role of tumour proliferation and p53 expression as a marker of survival in patients with urinary bladder cancer who undergo radical cystectomy.
Patients and methods: Samples were obtained from 31 patients (29 men and two women, mean age 66.0 years, range 46-80) with transitional cell carcinoma of the bladder who underwent radical cystectomy. The 31 formalin-fixed radical cystectomy specimens were stained immunohistochemically for Ki-67 antigen and p53 protein using MIB1 and p53 antibodies, respectively, and the results correlated with tumour grade, stages and prognosis.
Results: The Ki-67 index was significantly greater in high-grade tumours and in those overexpressing p53 (> 20% positive nuclei). Patients whose tumour samples had a high Ki-67 index (> 32%) had a significantly worse prognosis than those with a lower index (P < 0.01). There was a similar correlation between Ki-67 index and prognosis in high-risk patients (grade 3 and pT3-4; P < 0.05). Although the associations between tumour grade, stage and p53 expression were not statistically significant, patients whose tumour samples overexpressed p53 had a lower survival rate (P < 0.05). No patients with tumours having a low Ki-67 and low p53 index (n = 14) died of urinary bladder cancer during the follow-up.
Conclusion: These results suggest that immunohistochemical analyses for Ki-67 and p53 are useful prognostic indicators in patients with urinary bladder cancer who undergo radical cystectomy; the prognostic role of these markers was particularly important in high-risk (grade 3 and pT3-4) patients.