Renal cell carcinoma and upper tract urothelial carcinoma in kidney transplant recipients.

Renal cell carcinoma (RCC) is the most common solid-organ malignancy in Western countries, and upper tract urothelial carcinoma (UTUC) is the most common malignancy in Asian countries. The management of RCC/UTUC in kidney transplant recipients is complex and clinically challenging due to post-transplant modifications associated with immunosuppressive treatment. This retrospective study evaluated the incidence, risk factors, treatment outcomes, and oncological implications of RCC and UTUC in kidney transplant recipients from 2008 to 2023. Data were collected from clinical records, and follow-up calls for 20 patients diagnosed with RCC and UTUC among 2,283 kidney transplant recipients, revealing an incidence rate of 0.78% for RCC (18 patients) and 0.087% (two patients) for UTUC. Most patients presented localized disease at diagnosis. Surgical interventions included radical nephrectomy for the native kidney's RCC, radical or partial nephrectomy for allograft RCC, and radical nephroureterectomy for UTUC in the native kidney and allograft. Oncological outcomes indicated a mean follow-up of 51.29 months, during which five patients (25%) developed metastases, which achieved prolonged survival through surgical management, adjuvant therapy, and immunosuppression adjustments. The study highlights the increased cancer risk in this population and underscores the necessity for established screening protocols and individualized treatment strategies to optimize patient outcomes while preserving kidney function. These findings contribute to the ongoing research on managing malignancies in transplant recipients, with implications for further research and clinical guidelines.