Urinary collecting system invasion reflects adverse long-term outcome and is associated with simultaneous metastatic spread at the time of surgery and with multilocular dissemination during postsurgical follow-up in renal cell cancer

To assess the prognostic implication of urinary collecting system invasion (CSI) in renal cell cancer (RCC). Surveying a mean follow-up of 85 months, we investigated a cohort of 834 patients after radical (n = 710) or partial (n = 124) nephrectomy. At the time of surgery, 63 patients (7.6%) suffered from metastatic RCC. Various histopathologic parameters were analysed, and cancer specific survival (CSS) curves were individualized for each parameter. Furthermore, multivariate analysis was accomplished. Collecting system invasion was independently associated with a significant decline in CSS and was associated with simultaneous metastatic spread at the time of surgery and multilocular (involvement of at least two different organ systems) dissemination. The prognostic implication of CSI in RCC appears to be more complex than expected. Therefore, pathologists should report on CSI to enable selection of patients to be investigated in prospective studies which are needed to clarify the prognostic role of CSI in RCC.