Renal cell carcinomas in haemodialysis patients: does haemodialysis duration influence pathological cell types and prognosis?

Background. It is well known that renal cell carcinoma (RCC) is one of the most important complications in haemodialysis (HD) patients. However, the influence of HD duration on the development of RCCs has not yet been described. This study sought to determine whether HD duration is related to pathological RCC types and to prognosis. Methods. We examined 69 patients having HD (73 kidneys) who underwent radical nephrectomy for renal tumours between 1991 and 2008. We divided the patients into three groups according to the duration of HD (< 10 years, between 10 and 20 years, and > 20 years). All histological examinations were performed without knowledge of clinical outcomes. In each case, pathological cell types and clinical parameters were recorded. Results. The patients with HD duration of > 10 years showed distinct pathological characteristics, including acquired cystic disease of kidney-associated RCCs. The disease-free survival (DFS) rates of these groups were statistically different from one another (P < 0.05). RCC with a sarcomatoid component was found in cases having HD durations of > 10 years. The DFS rate of the patients with a sarcomatoid component was 55.9% at 5 years and 37.3% at 10 years. Conclusions. HD duration influenced pathological cell types and tumour stages of RCCs in HD patients. Patients receiving > 10 years of HD experienced RCCs with a sarcomatoid component, which resulted in poor outcomes. Hence, patients receiving long-term HD, and especially those with > 10 years of HD, should have frequent and careful medical examinations.