Về tỷ lệ tế bào ung thư biểu mô thận tồn tại cụ thể, 5 năm, 10year, và 15 năm tỉ lệ sống sót là 81,5%, 76,5% và 76,0%, tương ứng. Trong số 761 bệnh nhân đề cập đến lịch sử của phẫu thuật trong bảng câu hỏi, | Renal Cell Carcinomas in Dialysis Patients 53 Fig. 66. Observed survival rate and cancer-specific survival rate in dialysis patients with renal cell carcinoma surgical cases Reproduced from 58 with permission thereafter. Regarding the renal cell carcinoma-specific survival rates the 5-year 10year and 15-year survival rates were and respectively. Of the 761 patients who mentioned their history of surgery in the questionnaire 662 87 had undergone surgery. In these patients the mean age at the diagnosis of renal cell carcinoma was 52 years the mean duration of dialysis was 10 years and the mean postoperative follow-up period was years. The observed 5-year survival rate was which was close to the of those who did not develop renal cell carcinoma Fig. 66 . The cancer-specific 5-year survival rate was . These results suggest that the outcome is dependent on the age and stage of the tumor at diagnosis and that it is poorer as these are more advanced 58 . From our experience we consider that the mortality rate due to renal cell carcinoma . its prognosis is similar in dialysis patients and in the general population if the comparison is made between grade- and stage-matched subjects. However many investigators consider that the prognosis of renal cell carcinoma is better in dialysis patients than in the general population 11 111 112 . It is likely that this is primarily because renal cell carcinoma tends to be detected in an earlier stage in dialysis patients due to screening 105 . 10 Etiology History of Research into the Etiology I first evaluated whether there were mutagenic factors in cyst fluid in 1980. I requested the National Cancer Center to examine this by the Ames test but cyst fluid was 54 Acquired Cystic Disease of the Kidney and Renal Cell Carcinoma negative for mutagenic factors. An examination at our university also showed that the EGF level in the cyst fluid was not abnormally high. In addition no abnormality was noted
