[Transitional cell carcinoma of the upper urinary tract new concepts in management].

Transitional cell carcinomas of the upper urinary tract (UUT-TCCs) are rare: they account for approximately 5% of all urothelial carcinomas. 30% of patients with UUT-TCC have a history of bladder TCC, but fewer than 2% of patients with bladder TCC have UUT-TCC. Tumor microsatellite instability (MSI) is an indicator of the clonal expansion of neoplasms; it was first identified in tumors from patients with hereditary non-polyposis colorectal carcinoma (HNPCC). UUT-TCC occurs in 5% of patients with HNPCC. High-frequency microsatellite instability is present in almost 20% of cases of sporadic UUT-TCC. In cases of UUT-TCC with high-frequency MSI, hereditary cancer must be sought, especially if the patient is younger than 60 years or has a personal or family history of an HNPCC-related cancer: such patients should undergo DNA sequencing for the MSH2 gene germline mutation. Invasive UUT-TCC has a poor prognosis. 5-year survival is less than 50% for stage T2-T3 tumors and less than 10% for T4 or N+/M+ tumors. The main prognostic factors are age and tumor stage and grade. High-frequency MSI is a positive prognostic factor, especially in patients younger than 70 years with T2/T3/N0-M0 tumors.