The Clonal Origin Of Multifocal And Recurrent Low-grade Superficial Transitional Cell Carcinoma Of Bladder

Objective: To investigate the clonal origin of malignant cell in multifocal and recurrent low-grade superficial bladder cancer. Materials and Methods: We used a series of 20 cases of synchronous and/or metchronous multifocal low-grade superficial transition cell carcinoma of bladder and 66 multiple bladder carcinomas from them. The expression of p16, Rb and cyclin D1 were compared by means of immunohistochemical method in all tumors of a given patient. If the tumor is monoclonal, all tumors of a given patient should have the same immunoperoxidase staining. We calculated the probability for monoclonality using binomial distribution. Result: Sixteen patients had identical expression in the multiple carcinomas .which suggests that the carcinomas had a common origin, the probability for polyclonality was <0.033993. Four patients, however, had discordant expression, a fact that suggests independent origin. Conclusion: These results demonstrate that multiple bladder carcinomas seem to be either common or independent origin, but the common origin play the main role.