Collecting system invasion in renal cell carcinoma: impact on prognosis and future staging strategies.

Abstract

To define further the prognostic impact of urothelial invasion in renal cell carcinoma (RCC) we examined the outcome in patients presenting to our institution with kidney cancer treated with nephrectomy.
We reviewed the medical records of 895 patients with RCC who were treated with nephrectomy between 1989 and 1999. Median followup was 31 months. Kaplan-Meier survival curves were constructed with respect to 1997 TNM stage, Fuhrman grade and University of California-Los Angeles Integrated Staging System stage, comparing patients with and without collecting system invasion. Univariate and multivariate analyses were performed. Overall survival was defined as time from nephrectomy to time of death or last followup.
Of the 895 patients 124 (14%) demonstrated collecting system invasion. Patients with collecting system invasion were more likely to be symptomatic and have associated metastases and/or positive nodes at diagnosis. Urothelial invasion was evident in 21 of 329 T1, 12 of 131 T2, 84 of 388 T3 and 7 of 47 T4 tumors. Three-year overall survival for patients with vs without collecting system invasion by stage was 67% vs 81% for T1, 60% vs 69% for T2, 31% vs 46% for T3 and 29% vs 12% for T4 disease. Patients with urothelial invasion incurred a significant increase in the likelihood of death and were at 1.4 times greater risk of death compared with patients without collecting system invasion.
Our findings suggest that collecting system invasion in RCC cases is associated with specific clinical findings as well as poor prognostic variables and it has a profound impact on prognosis in low stage tumors.