Prognostic value of the involvement of the urinary collecting system in renal cell carcinoma

The prognostic role of the invasion of the urinary collecting system (UCS) by renal cell carcinoma (RCC) has not attracted a notable amount of attention. The aim of this study was to investigate incidence and prognostic value of UCS involvement in RCC.All pathological reports of radical nephrectomies performed in two centres of urology from November 1983 to December 1999 were reviewed in order to evaluate the invasion of the UCS (calices, renal pelvis, ureter). Patients were divided into two groups according to presence (Group 1) or absence (Group 2) of UCS invasion. The stage was determined according to the TNM 6th edition. Overall and cause-specific survival rates were evaluated. Univariate and multivariate analyses were performed.The evaluable specimens were 671 from the 735 examined; in 64 cases it was not possible to ascertain or to exclude UCS involvement. Invasion of the UCS was found in 59 cases (8.8%). Median follow-up was 59.0 months (range 0-216). Tumours invading the UCS were usually symptomatic, with high nuclear grade and predominantly high stage. At univariate analysis the 5 year overall and cause-specific survival rates of tumours invading the UCS were significantly lower when compared to those without UCS invasion (42.8% versus 60.8% and 45.5% versus 64.7%, respectively). When groups were stratified, according to the pT category, the 5-year cause-specific survival rate was only significantly different for the pT2 category (33.3% versus 76.9%). At the multivariate analysis TNM staging, symptoms at diagnosis and tumour grade were the only independent prognostic factors.The invasion of the UCS by RCC is unusual, particularly in small tumours. UCS involvement does not represent an independent prognostic factor. However, in organ-confined tumours (i.e. pT2) UCS involvement has an influence on the prognosis and should be taken into account when planning adjuvant treatments and follow-up.