Aims: To determine the incidence and recent trends of renal cell carcinoma (RCC) in dialysis patients, a nationwide investigation was performed in Japan. Methods: In February 2002, 3,155 questionnaires were sent to dialysis units in Japan. The variables studied for RCC diagnosed between March 2000 and February 2002 included patient age, duration of dialysis, diagnostic aids, cancer size, histology of cancer, and the presence of metastasis and acquired cysts. Results: 489 RCCs (381 males, 104 females, and 4 unknown) were studied. The mean age of the RCC patients was 57.5+/-11.4 (mean+/-SD) years, and the mean duration of dialysis was 136.9+/-95.2 months. RCC was detected by symptoms alone in 5.3% of the cases, by sonographic screening in 46.1%, and computed tomographic screening in 44.2%. The metastasis rate was 15.2%. The standardized incidence ratio was 9.7 (95% confidence interval, CI: 8.3-11.2) for the male dialysis patients and 11.0 ( 95% CI: 8.2-14.4) for the female patients. Eighty-four of the RCC patients with more than 20 years of hemodialysis were younger, were more frequently male, and demonstrated a larger cancer size, a higher incidence of papillary RCC, a higher metastasis rate, and a higher incidence of fatal RCC than 215 patients with less than 10 years of dialysis. Conclusion: 54.6% of the patients with RCC received dialysis for more than 10 years. For RCC patients with more than 20 years of dialysis, the mean age was younger, and the metastasis rate was higher than for RCC patients with less than 10 years of dialysis. Copyright (C) 2004 S. Karger AG, Basel.
