Development of urologic de novo malignancies after renal transplantation.

OBJECTIVES: The incidence of neoplasms in renal transplant recipients is higher than in general population. The increasing age of donors and recipients also increases the risk of developing malignancies, including genitourinary. The aim of this study is to analyze clinical aspects and management of this complication.

MATERIALS AND METHODS: We conducted a retrospective analysis of 1365 patients who underwent renal transplantation between 1977 and 2010 who were 44.6 ± 14.9 years old at the time of transplantation. The median follow-up was 95.6 months (range, 18.0-236.0). Data were analyzed for sex, age, time from transplant to diagnosis, location, clinical stage, immunosuppression, treatment, follow-up, and evolution.

RESULTS: We diagnosed 25 de novo urologic neoplasms (25/1365; 1.8%) in 24 patients, with a median follow-up of 32 months (range, 12.5-51.8) from the diagnosis. Sixteen were male (66.7%) and 8 female (33.3%), with a median age at diagnosis of 59 years (range, 56.0-65.5). The median time between the transplant and the diagnosis of the malignancy was 69 months (range, 40.0-116.5). There were 11 renal cell carcinomas (RCC; 11/25; 44%), 8 in native kidney and 3 in renal allograft; 9 prostate cancers (PCa; 9/25; 36%), 8 localized and 1 metastatic; and 5 transitional cell carcinomas (TCC; 5/25; 20%), 3 in bladder and 2 in renal allograft pelvis. Treatments performed were similar to those used in the nontransplanted population. RCC were treated with radical nephrectomy when affecting the native kidney, partial nephrectomy when affecting the allograft, or immunotherapy when metastatic. Patients with localized PCa were treated with radical prostatectomy, radiotherapy, or androgenic deprivation if there were comorbidities, and those metastatic with hormonal deprivation. Bladder TCCs were treated with transurethral resection or radical cystectomy. Pelvis TCCs affecting the allograft were treated with radical nephroureterectomy of the allograft including bladder cuff and pelvic lymphadenectomy.

CONCLUSIONS: There exists an increased incidence of urologic tumors in kidney transplant recipients. Conventional treatments of these tumors are technically feasible. The risk of developing these tumors remains even in the long term. Because of their suitability for curative treatments, it is advisable to perform periodic screening for urologic cancers to achieve an early diagnosis.