Urinary collecting system invasion is associated with poor survival in patients with clear-cell renal cell carcinoma

Objectives To evaluate the prognostic significance of urinary collecting system invasion (UCSI) in a large series of patients with clear-cell renal cell carcinoma (RCC). Materials and Methods Patients with clear-cell RCC treated with nephrectomy between 2001 and 2010 were reviewed from a prospectively maintained registry. One urological pathologist re-reviewed all slides. Cancer-specific survival was estimated using the Kaplan-Meier method, and associations of UCSI with death from RCC were evaluated using Cox models. Results Of the 859 patients with clear-cell RCC, 58 (6.8%) had UCSI. At last follow-up, 310 patients had died from RCC at a median of 1.8 years after surgery. The median follow-up for patients alive at last follow-up was 8.2 years. The estimated cancer-specific survival at 10 years after surgery for patients with UCSI was 17%, compared with 60% for patients without UCSI (P < 0.001). In a multivariable model, UCSI remained independently associated with an increased risk of death from RCC (hazard ratio 1.5; P = 0.018). Further, among patients with pT3 RCC, those with USCI had survival outcomes similar to those of patients with pT4 RCC. Conclusions Collecting system invasion is associated with poor prognosis among patients with clear-cell RCC. If validated, consideration should be given to including UCSI in future staging systems.