Effect of subsequent bladder cancer on survival in upper tract urothelial carcinoma patients post-radical nephroureterectomy: a systematic review and meta-analysis

Radical nephroureterectomy (RNU) is the primary treatment strategy for upper tract urothelial carcinoma (UTUC). However, the intravesical recurrence occurs in 20-50% of all patients. The specific effect of subsequent bladder cancer (SBCa) on survival remains unclear. Therefore, we investigated the effect of SBCa following RNU in patients with UTUC.PubMed, EMBASE, and Cochrane Library were exhaustively searched for studies comparing oncological outcomes between SBCa and without SBCa. Standard cumulative analyses using hazard ratios (HR) with 95% confidence intervals (CI) were performed using Review Manager (version 5.3).Five studies involving 2057 patients were selected according to the predefined eligibility criteria. Meta-analysis of cancer-specific survival (CSS) and overall survival (OS) revealed no significant differences between the SBCa and non-SBCa groups. However, subgroup analysis of pT0-3N0M0 patients suggested that people with SBCa had worse CSS (HR = 5.13, 95%CI 2.39-10.98, p < 0.0001) and OS (HR = 4.00, 95%CI 2.19-7.31, p < 0.00001).SBCa appears to be associated with worse OS in patients with early stage UTUC. However, caution must be taken before recommendations are made because this interpretation is based on very few clinical studies and a small sample size. Research sharing more detailed surgical site descriptions, as well as enhanced outcome data collection and improved reporting, is required to further investigate these nuances.