Tumor markers in stage P1 bladder cancer

Background: The infiltration of muscularis mucosa in superficial bladder ca ncer has been reported to be predictive of an unfavourable course of the di sease. Materials and Methods: We studied immunohistochemically Ki-67, PCNA and p53 tumour markers in 68 P1a and Pib bladder tumours. Results: A statis tically significant difference (p=0.01) was found in the distribution of gr ades between stages P1a and P1b, with mon grade 3 and less grade 2 tumours in the latter category. Univariate analysis revealed a strong association o f Ki-67 (p=0.001) and PCNA (p=0.032) only with stage. P53 protein expressio n did not have any significant association with either stage or grade. In 6 0 patients entered into the multivariate analysis a clearly predominant, si gnificant effect of stage on Ki-67 (p=0.000) was shown. Conclusion: Ina eas ed proliferative activity when compared to P1a is present in P1b bladder tu mours, as detected by the increased expression of Ki-67 proliferating antig en. The immunohistochemical study of Ki-67 antigen may help in predicting s tage P1 tumours' behaviour; even in cases where pathological distinction of P1a and P1b substages is difficult.