Renal cell carcinoma in kidney transplant recipients: incidence, trends, clinical management & outcomes.

OBJECTIVE: To describe the incidence, characteristics, clinical management, and outcomes of renal cell carcinoma (RCC) among a large, single-centre cohort of kidney transplant recipients (KTR). METHODS: We conducted an observational cohort study looking at KTR transplanted between January 2000-December 2017 (n = 2443) with ≥ 1 year of follow-up. Simultaneous kidney/pancreas transplants were excluded. The Kaplan-Meier product-limit method was used to determine the incidence of RCC. Characteristics and management of RCC were examined using descriptive statistics. Risk factors and clinical outcomes were analyzed using Cox regression models. RESULTS: The incidence of RCC among our cohort was 0.32 per 100 person-years, 2.1% of all KTRs. Almost half (47.1%) of cases occurred within 4 years post-transplant. The majority of cases were T1a (86.3%), clear-cell (45.1%), and in the native kidney (80.4%). KTR diagnosed with RCC had a twofold higher incidence of other malignancies versus KTR without RCC. Overall mortality, but not cancer-specific mortality, at 2- and 5-years post-transplant was threefold higher among KTR with RCC than those without. CONCLUSIONS: Incidence of RCC among our KTR was slightly higher than the general population; majority of cases occur in the native kidneys and are low stage, low grade. Indolent histologic variants were more common than the general population. KTR with RCC had a higher incidence of other malignancies. Overall, but not cancer-specific, mortality was higher among KTRs diagnosed with RCC.