Invasion of the urinary collecting system is an independent prognostic factor in pT3 renal cell carcinoma

Abstract

Objective: To evaluate the prognostic significance of urinary collecting system invasion (UCSI) in pT3 renal cell carcinoma (RCC).

Patients and methods: Patients undergoing nephrectomy for renal masses with pathological stage T3 RCC at our institution from 2006 to 2014 were identified. The entire cohort was divided into 2 groups according to the presence of UCSI. Clinicopathological variables were collected and compared using Student's t-test or chi-square test. Kaplan-Meier survival analysis and multivariate Cox regression were performed to determine the effect of UCSI on survival outcomes.

Results: Of the 218 patients with pT3 RCC enrolled in this study, 68 (31.2%) presented with UCSI. The presence of UCSI was associated with higher rates of symptoms at diagnosis (P<0.001), larger tumor sizes (P = 0.004), higher Fuhrman grades (P = 0.018), lower proportions of perirenal fat invasion (P = 0.024), and higher probabilities of having tumor necrosis (P = 0.024) and positive lymph nodes (P<0.001). When compared with those without UCSI, patients with UCSI showed shorter estimated 5-year cancer-specific survival rates (33.5% vs. 55.8%, P<0.001) and 5-year progression-free survival rates (27.4% vs. 44.3%, P<0.001). Multivariate analysis revealed that UCSI was independently associated with poorer cancer-specific survival rates (hazard ratio = 1.76, 95% CI: 1.12-2.78, P = 0.015) and progression-free survival rates (hazard ratio = 1.82, 95% CI: 1.23-2.68, P = 0.003).

Conclusion: UCSI appears to be an independent prognostic factor of pT3 RCC and may be considered in future TNM systems to help stratify different prognoses. More attention should be paid to patients with pT3 RCC with UCSI and close follow-up is recommended to improve survival rates.

Keywords: Pathological stage T3; Prognostic factor; Renal cell carcinoma; Urinary collecting system invasion.