Impact of diagnostic ureteroscopy on intravesical recurrence in patients undergoing radical nephroureterectomy for upper tract urothelial cancer: a systematic review and meta-analysis

Aim of this study was to analyse the association between the use of diagnostic ureteroscopy (URS) and the development of intravesical recurrence (IVR) in patients undergoing radical nephroureterectomy (RNU) for high-risk upper tract urothelial carcinoma. A systematic review of the published data was performed up to December 2016, using multiple search engines to identify eligible studies. A formal meta-analysis was conducted of studies comparing patients who underwent URS before RNU with those who did not. Hazard ratios (HRs), with their 95% confidence intervals (CIs), from each study were used to calculate pooled HRs. Pooled estimates were calculated using a fixed-effects or random-effects model according to heterogeneity. Statistical analyses were performed using REVMAN, version 5. Seven studies were included in the systematic review, but only six of these were deemed fully eligible for meta-analysis. Among the 2 382 patients included in the meta-analysis, 765 underwent diagnostic URS prior to RNU. All examined studies were retrospective, and the majority examined Asian populations. The IVR rate ranged from 39.2% to 60.7% and from 16.7% to 46% in patients with and without prior URS, respectively. In the pooled analysis, a statistically significant association was found between performance of URS prior to RNU and IVR (HR 1.56, 95% CI 1.33-1.88; P < 0.001). There was no heterogeneity in the observed outcomes, according to the I-2 statistic of 2% (P = 0.40). Within the intrinsic limitations of this type of analysis, these findings suggest a significant association between the use of diagnostic URS and higher risk of developing IVR after RNU. Further research in this area should be encouraged to further investigate the possible causality behind this association and it potential clinical implications.