Introduction

In excess of 90% of tumors arising from the urinary bladder are urothelial carcinomas [1]. Alternative histological cell types which may rarely be encountered include squamous cell carcinoma, adenocarcinoma and tumors of mesenchymal origin.

Bladder cancer is a cause of significant morbidity and mortality throughout the world. Statistics demonstrate that between the years 2001 and 2003, 10 264 new cases of bladder cancer were diagnosed in the United Kingdom, and it was the seventh most common cause of malignancy-related death in males and eleventh most common cause in females [2]. Bladder cancer typically occurs in later life, with the peak incidence in the sixth and seventh decades. This, together with the strong association with environmental factors, likely accounts for the significant worldwide variation in incidence with, e.g. the incidence in the Italian male population being in excess of six times that in the Indian male population [3].

The prognosis of bladder cancer is dependent on a number of factors. Of particular importance are the depth of bladder wall invasion, the presence of metastases in lymph nodes and the presence of blood-borne metastases. In cases of superficial transitional cell malignancy, mean five-year survival of approximately 80% can be expected. Invasive tumors reduce five-year survival to less than 50%. If nodal metastases or blood-borne metastases are present then the five-year survival rate is worse still (15 and 5% respectively) [4,5]. Depending on local practice, up to one-third of patients may have metastatic disease at presentation [6].