Clinical and pathological outcomes of renal cell carcinoma (RCC) in native kidneys of patients with end-stage renal disease: a long-term comparative retrospective study with RCC diagnosed in the general population.

PURPOSE: Patients with end-stage renal disease (ESRD) have an increased risk of developing renal cell carcinoma (RCC). This retrospective study compared clinical and pathological outcomes of RCC occurring in native kidneys of patients with ESRD (whether they underwent kidney transplantation or not) with those of renal tumors diagnosed in the general population. METHODS: The study included a total of 533 patients with RCC. The ESRD cohort included 92 patients with RCC in native kidneys. Of these, 58 and 34 cases were identified before (pre-Tx group) and after kidney transplantation (post-Tx group), respectively. The control group was composed of 441 RCCs diagnosed in the general population. Variables were compared by chi-square and Student's t tests. Cancer-specific survival was assessed by Kaplan-Meier and Cox methods. RESULTS: The ESRD groups had smaller (P = 0.001), lower-grade, and lower-stage tumors than the non-ESRD group (P = 0.001). The papillary RCC rate was higher in the ESRD groups (P = 0.01). Ten-year cancer-specific survivals were 94.5, 87.9, and 74.6 % in pre-Tx, post-Tx, and non-ESRD patients, respectively (P = 0.003). Mean follow-up was 90.2 months. At multivariate analysis, tumor size (HR = 1.10), pathological stage (HR = 1.46), presence of nodal (HR = 2.22) and visceral metastases (HR = 3.49), and Fuhrman grade (HR = 1.48) were independent adverse prognostic factors for cancer-specific survival. CONCLUSIONS: Native kidney RCCs arising in ESRD patients are lower stage and lower grade as compared to RCCs diagnosed in the general population, and these tumors exhibit favorable clinical and outcome features.