Based on pooled analysis, the incidence of IVR is approximately 29% (range 21-46%). Median time to IVR was 22 months (6.7-57 months).
As mentioned earlier, the pathophysiology of IVR may be two-fold: tumor seeding from free-floating UTUC cancer cells (multiclonal) or a pan-urothelial defect predisposing to urothelial disease in all areas of the urinary tract (polyclonal).
In terms of prevention, he cited the O’Brien study (European Urology, 2011) that demonstrated bladder recurrence-free survival improvement after RNU with a single-dose mitomycin-C. Hence, the guidelines strongly recommend a single post-operative dose of bladder chemotherapy instillation to lower IVR.
He then went through, quickly, the results of the meta-analysis. There were tumor-specific, patient-specific and treatment-specific risk factors that were noted. The manuscript has full details regarding the analysis. A summary slide below was an excellent overview of the findings:
Those high-risk patients should definitely receive the post-operative MMC instillation.
In terms of treatment-specific factors that are modifiable, he noted that laparoscopic RNU and extravesical bladder cuff excision are predictors of IVR. Both are probably related to incomplete bladder cuff excision. He recommends that careful attention should be paid attention to bladder cuff excision at time of laparoscopic RNU, but does not recommend stopping the procedure.
He lastly followed up on Dr. Baard’s talk by noting that diagnostic ureteroscopy prior to RNU may increase risk of IVR, and the guidelines therefore recommend strongly that dURS should be considered. Hence, if dURS is utilized, a higher risk IVR is expected – and intravesical MMC should be given after RNU.
Presented by: T. Seisen, Paris, France
Written by: Thenappan Chandrasekar, MD Clinical Fellow, University of Toronto, twitter: @tchandra_uromd at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark