Baboudjian M, Al-Balushi K, Michel F, et al. - Investigators sought to assess the impact of a standardized diagnostic flexible ureteroscopy (DFU) technique before radical nephroureterectomy (RNU) on the risk of bladder recurrence (BR). Individuals (n = 171) undergone RNU for upper tract urothelial carcinoma (UTUC) were involved in a retrospective monocenter study between 2005 and 2017. With a history of bladder cancer prior to RNU or neo-adjuvant/adjuvant chemotherapy, 78 people were rejected. According to pre-RNU ureteroscopy or no pre-RNU ureteroscopy, 93 involved people were stratified. It was found that a high bladder recurrence following diagnostic ureteroscopy + nephroureterectomy in spite of technical precautions to evade contact of bladder mucosa with contaminated urine from the upper urinary tract. Moreover, post-DFU endovesical instillation shall be investigated.