Studies of heterotransplantation of transplantable human urogenital malignant neoplasms, 6

Radiotherapeutic effects were studied using human urinary bladder cancer (NM-B-1) and human prostatic cancer (Pro-1) transplantable to nude mice. NM-B-1 is a poorly differentiated transitional cell carcinoma and Pro-1 is a poorly differentiated adenocarcinoma. In both the 24th to 27th passage of NM-B-1 and the 35th to 38th passage of Pro-1, the successful transplantation rates were almost 100 per cent and the growth rates were similar and stable. Two weeks after subcutaneous transplantation of the tumor, electron beam irradiation was performed locally using a linear accelerator. The therapeutic effects were evaluated on the tumor growth curve, as well as light and electron microscopic findings. The standard deviations of the tumor volumes were relatively small in all radiated groups and this study seemed applicable to radiosensitivity test. On the tumor growth curve, significant tumor regressive effects were observed statistically in a dose of 12 Gy for NM-B-1 and 6 Gy or more for Pro-1, respectively, and dose-dependency was seen in the effects. Stromal degeneration and destruction of cancer cells were demonstrated by light and electron microscopy in both NM-B-1 and Pro-1 two weeks after irradiation of 18 Gy. (author)