The Risk of Tumour Recurrence in Patients Undergoing Renal Transplantation for End-stage Renal Disease after Previous Treatment for a Urological Cancer: A Systematic Review

CONTEXT: Renal transplantation is the gold standard renal replacement therapy in end-stage renal disease owing to its superior survival and quality of life compared with dialysis. When the potential recipient has a history of cancer, the waiting period before renal transplantation is usually based on the Cincinnati Registry. OBJECTIVE: To systematically review all available evidence on the risk of cancer recurrence in end-stage renal disease patients with a history of urological cancer. EVIDENCE ACQUISITION: Medline, Embase, and the Cochrane Library were searched up to March 2017 for all relevant publications reporting oncologic outcomes of urological cancer in patients who subsequently received a transplantation or remained on dialysis. The primary outcome was time to tumour recurrence. Secondary outcomes included cancer-specific and overall survival. Data were narratively synthesised in light of methodological and clinical heterogeneity. The risk of bias of each included study was assessed. EVIDENCE SYNTHESIS: Thirty-two retrospective studies enrolling 2519 patients (1733 dialysed, 786 renal transplantation) were included. For renal cell carcinomas, the risks of recurrence, cancer-specific, and overall survival were similar between transplantation and dialysis. For prostate cancer, most of the tumours had favourable prognoses consistent with nomograms. Studies dealing with urothelial carcinomas (UCs) mainly included upper urinary tract UC in the context of aristolochic acid nephropathy, for which the risks of synchronous bilateral tumour and recurrence were high. Data on testicular cancer were scarce. CONCLUSIONS: Immunosuppression after renal transplantation does not affect the outcomes and natural history of low-risk renal cell carcinomas and prostate cancer. Therefore, the waiting time from successful treatment for these cancers to transplantation could be reduced. Except in the particular situation of aristolochic acid nephropathy, more studies are needed to standardise the waiting period after UC owing to the paucity of data. PATIENT SUMMARY: Renal transplantation does not appear to increase the risk of recurrence of renal carcinoma or the recurrence of low-risk prostate cancer compared with dialysis. More reliable evidence is required to recommend a standard waiting period especially for urothelial and testicular carcinomas.