Renal cell carcinoma co-existent with other renal disease: clinico-pathological features in pre-dialysis patients and those receiving dialysis or renal transplantation

Background. Patients on chronic dialysis are prone to developing acquired cystic kidney disease (ACKD), which may lead to the development of renal cell carcinoma (RCC). The risk factors for the development of RCC so far have not been determined in predialysis patients with co-existent renal disease. The aim of this study was to evaluate the clinicopathological features of RCC in pre-dialysis patients with associated renal diseases or in those undergoing chronic dialysis and renal transplantation. Methods. We studied 32 kidneys from 31 patients with RCC and associated renal diseases. Of those, 18 kidneys were from 17 patients not on renal replacement therapy (RRT) when diagnosed with RCC; 14 patients received dialysis or dialysis followed by renal transplantation. Several clinico-pathological features were analysed and compared between the two groups. Results. Overall, there was a preponderance of males (75%); nephrosclerosis was the predominant co-existent disease (31%). The median intervals from renal disease to RCC in the dialysis and transplanted groups were significantly longer than in the pre-dialysis group (15.8±1.1 vs 2.4±0.7 years, P<0.0001). In contrast to pre-dialysis RCC, the dialysis and transplant RCC groups had greater frequency of ACKD (100 vs 28%, P<0.0001), papillary type RCC (43 vs 11%, P<0.05) and multifocal tumours (43 vs 5%, P<0.05). At the end of the study, 71% of dialysis and transplanted patients and 72% of pre-dialysis patients were alive. Conclusions. ACKD develops in dialysis patients, as it does in those with renal disease prior to RRT. The duration of renal disease, rather than the dialysis procedure itself, appears to be the main determinant of ACKD and RCC. The RCC occurring in patients with ACKD and prolonged RRT is more frequently of the papillary type and multifocal than the RCC occurring in patients with no or few acquired cysts and a short history of renal disease. Long-term outcomes did not differ between the two groups.