Sirolimus Does Not Absolutely Abolish the Occurrence/Recurrence of Urothelial Carcinoma in Renal Transplant Recipients

Objective. Sirolimus (SRL), an immunosuppressant shown to possess anti- proliferative properties, was hypothesized to mitigate the occurrence of posttransplantation malignancy. We examined its effect on posttransplantation urothelial carcinoma (UC). Methods. This retrospective case analysis included renal allograft recipients with UC treated with SRL in a single institute. Results. Among 90 renal recipients treated with SRL, 6 had previous/new-onset UC in the native kidney/ureter or bladder: at a mean period of 28 months ( range, 7-49) of administering SRL for these recipients, UC occurred/recurred in 4 of the 6 patients. Individual cases are presented in detail. Conclusion. SRL does not absolutely abolish the occurrence/recurrence of UC among renal transplant recipients. Its potency as an anti-cancerous immunosuppressant for transplant recipients with UC deserves to be further defined in larger studies, probably by controlling SRL blood levels at lower or much higher ranges than used herein