Bacillus Calmette‐Guerin therapy in non‐muscle‐invasive bladder carcinoma after renal transplantation for end‐stage aristolochic acid nephropathy

Intravesical instillation of bacillus Calmette‐Guerin (BCG) is the treatment of choice for non‐muscle‐invasive bladder cancer (NMIBC) of high grade and/or carcinoma in situ. This study evaluated the feasibility, efficacy, and tolerance of BCG instillations in eight kidney recipients for end‐stage aristolochic acid nephropathy (AAN), a condition at high risk of urothelial carcinoma, and diagnosed for NMIBC. Five of them had relapsed after mitomycin C treatment. Tolerance to BCG was evaluated clinically and regular follow‐up with fluorescence cystoscopy was performed along with renal graft function monitoring. Immunosuppression doses were adjusted and prophylactic anti‐tuberculous treatment given to reduce risks of graft rejection and infection. After a mean follow‐up period of 50 months, seven of the eight patients are free of relapse and kidney graft function remained unchanged. Tolerance was good, except for one episode of fever and one early discontinuation because of subjective discomfort. No systemic tuberculous infection was observed. This is the first clinical observation of successful BCG therapy for NMIBC in patients given transplant for end‐stage AAN. Under standardized conditions, immunotherapy based on intravesical BCG is feasible, effective, and well tolerated in renal transplantation.