[Primary upper urinary tract tumors and subsequent location in the bladder]

The urothelium is the epithelium that lines the upper and lower urinary tract. Over 95% of urothelial carcinomas are derived from urothelium. They can be located in the lower tract (bladder, urethra) or upper tract (pyelocaliceal cavities, ureter). Urothelial carcinomas are the fourth most common tumours after prostate (or breast) cancer, lung cancer and colorectal cancer. On one hand, bladder tumours account for 90-95% of urothelial carcinomas. It is the most common malignancy of the urinary tract and the second most common malignancy of the urogenital tract after prostate cancer. It accounts for 5-10% of all cancers diagnosed each year in Europe. On the other hand, upper urinary tract urothelial cell carcinomas (UUT-UCC) are scarce and account for only 5-10% of urothelial carcinomas. Recurrence in the bladder after primary UUT-UCC occurs in 15-50% of UUT-UCC. Differences in treatment modalities of the primary UUT-UCC do not play a key role in the subsequent appearance of a bladder recurrence. However, others factors have been described such as stage and location in the upper tract of the primary tumour or upper tract tumour multifocality. Previous history of bladder tumour is also associated with the risk that another tumour arises in the bladder subsequently. However, it becomes difficult to distinguish between natural history of bladder tumour and evolution of UUT-UCC in these cases. In most cases, bladder cancer occurs in the first two years after UUT-UCC management. Surveillance protocol is based on cystoscopy and on urinary cytology during at least every three months for two years. Current surveillance regimen have a low level of evidence considering the paucity of UUT-UCC.