Prognostic role of urinary collecting system invasion in renal cell carcinoma: a systematic review and meta-analysis

The relationship between urinary collecting system invasion (UCSI) and oncological outcomes in renal cell carcinoma (RCC) patients has attracted extensive attention recent years. However, the reports were inconsistent and remain controversial. Thus, we performed a systematic literature search of PubMed, Embase, Web of Science and The Cochrane Library databases to identify relevant studies up to June 2015 and conducted a standard meta-analysis of survival outcomes. 17 studies containing 9012 RCC patients satisfied the inclusion criteria. Pooled HRs for overall survival (OS) and recurrence-free survival (RFS) were 1.45 (95% CI, 1.26–1.66, P < 0.001) and 2.27 (95% CI, 1.54–3.34, P < 0.001), respectively. Further subgroup analysis suggested that UCSI was significant associated with poor cancer-specific survival (CSS) in stage T1–T2 RCC (HR = 2.05, 95% CI: 1.43–2.96, P < 0.001) but not in stage T3–T4 tumors (HR = 1.08, 95% CI: 0.63–1.85, P = 0.771). Current evidence revealed that UCSI has a significant negative impact on OS and RFS in RCC patients and could be used to predict CSS especially in localized RCC. Thus, RCC patients with UCSI should be paid more attention by clinician and pathologist and require close follow up for their poor prognosis.