Urinary collecting system invasion in renal cell carcinoma: Incidence and long-term prognosis

Objectives: Current data on the prognostic impact of urinary collecting system (UCS) invasion by renal cell carcinoma (RCC) are highly conflicting. The aim of the present study was to assess incidence and long-term prognosis of RCC patients with and without UCS involvement. Methods: We evaluated 780 patients who had undergone renal surgery between 1990 and 2005. The mean follow-up was 5.44 years. Results: Sixty-seven patients (8.6%) demonstrated UCS invasion. These patients had a significant increase in the likelihood of cancer-related death (hazard ratio [HR] 1.9, 95% confidence interval: 1.4-2.7; P = 0.001). Their median 5-year tumor-specific survival rate was 61%, as opposed to 79% for patients without UCS invasion (P = 0.001). UCS invasion was significantly associated with tumor stage, grade, clinical symptoms, lymph node and visceral metastasis at diagnosis, but not with age, gender, histologic subtype or body mass index. However, by means of multivariate analysis, UCS invasion was disqualified as an individual prognostic marker for RCC. Conclusion: We do not advocate the inclusion of UCS invasion into upcoming Tumor-Nodes-Metastasis staging systems. In contrast, future research should focus on the prognostic role of novel molecular tumor markers and/or specific immunological characteristics of RCC patients.