RENAL CELL AND TRANSITIONAL CELL CARCINOMA IN A JAPANESE POPULATION UNDERGOING MAINTENANCE DIALYSIS

Abstract

We verified differences in the incidence, clinical characteristics and outcomes between patients on chronic dialysis for end stage renal disease with renal cell carcinoma (RCC) and those with transitional cell carcinoma (TCC). Data regarding RCC and TCC were reviewed in the medical records of 6,201 patients with end stage renal disease who underwent chronic dialysis between January 1990 and June 2003 in our 38 affiliated dialysis centers, and data were compared with those reported in Australia and New Zealand. Among the patients RCC developed in 38 (0.61%) and TCC developed in 16 (0.26%) during maintenance dialysis. The primary renal disease was chronic glomerulonephritis in patients with RCC (68.4%) and diabetic nephropathy in patients with TCC (43.8%, p = 0.002). Mean patient age at initiation of dialysis was 45 years for those with RCC and 63 for those with TCC (p < 0.001). Mean interval from dialysis induction to tumor diagnosis was 143 months for patients with RCC and 54 months for patients with TCC (p < 0.001). Of 38 RCCs 23 (60.5%) were incidentally detected by regular abdominal imaging examinations while painless gross hematuria was the cardinal symptom in 13 (81.2%) of 16 TCCs. Overall and cancer specific survivals after tumor diagnosis were significantly superior in patients with RCC compared to those with TCC (p = 0.0001 and p = 0.0003, respectively), and the cancer specific 5-year survival was 88.9% for RCC and 29.5% for TCC. In both cancers tumor stage significantly increased the risk of cancer specific death. Compared with patients from Australia and New Zealand, the incidence of RCC was higher and that of TCC was lower in our patients (p <0.001). In the Japanese population on dialysis RCC is more common than TCC. Since long-term dialysis is a risk factor for RCC, regular imaging examinations may have contributed to the favorable outcome of our patients on dialysis with RCC. In contrast, the unfavorable outcome of TCC suggests the need for effective diagnostic measures for early detection of TCC in patients on dialysis.