Urothelial carcinomas of the upper urinary tract are now recognised as a true and distinct entity from bladder cancer and belong fully to the broad spectrum of onco-urologic neoplasms

Excerpt

The urothelium is the epithelium that lines the upper and lower urinary tracts. Over 95 % of urothelial carcinomas are derived from the urothelium [1‐3], and they can be located in the lower tract (bladder, urethra) or upper tract (pyelocaliceal cavities, ureter). Bladder cancer is ranked the 11th most common cancer in the world, and over 50 % of cases occur in developed countries [1, 3]. However, upper urinary tract urothelial carcinomas (UTUCs) are scarce and account for only 5–10 % of urothelial carcinomas. The estimated annual incidence in western countries is approximately 2 new cases/100,000 inhabitants [1, 3]. Pyelocaliceal tumours are approximately twice as common as ureteral tumours. Although the mechanisms of carcinogenesis are thought to be similar throughout the urinary tract, recent epidemiological data and genetic studies suggest otherwise. The natural history of UTUCs differs from that of bladder cancer; 60 % of UTUCs are invasive at diagnosis compared to only 15 % of bladder tumours. Apart from these epidemiological considerations, one could consider urothelial carcinomas as a whole and underline that the distinction between tumours of the upper and of the lower urinary tracts should be anatomically based (i.e. upper urinary tract vs. lower urinary tract). Recent data suggest that this was, by far, a too Manichean vision of the problem. It is now obvious that strong differences exist regarding tumour location and behaviour between the upper and lower urinary tracts. …