Tumour cell expansion in bladder epithelium

Bladder cancer is common in western society. The major problem of patients with superficial bladder cancer is the high recurrence rate and multifocality of these tumours. In 70 % of the patients superficial bladder cancer recurs after local resection of the tumour within 15 years. The tumour recurrences are probably caused by tumour cells that were not removed by the therapy. These residual tumour cells apparently can form secondary tumours at multiple sites in the bladder mucosa. In this respect bladder cancer is different from other carcinomas. Factors involved in the normal physiology of the bladder epithelium may also attribute to the expansion of tumour cells and the recurrence of bladder carcinomas. In order to provide better understanding of the process of bladder cancer recurrence the anatomy and histology of the urinary bladder and the carcinogenesis of bladder carcinoma are described in paragraphs 1.1 and 1.2. In paragraph 1.3 the development of tumour recurrences is described and a hypothesis is developed regarding the role of extracellular matrix components, growth factors and adhesion molecules in the development of recurrences, either by affecting the normal bladder epithelium or by affecting the bladder carcinoma cells themselves (paragraph 1.4).