TREATMENT IN ESTABLISHED HUMAN RENAL CELL CARCINOMA HETEROTRANSPLANTED IN NUDE MICE : 4. Experimental Treatment with Benzaldehyde Derivative and Combination Therapy with Irradiation

A study was conducted to the carcinostatic agent benzaldehyde derivative (BG) and combination therapy with BG and irradiation used to treat human renal cell carcinoma serially transplanted to nude mice (JRC 11). Two different doses of BG were examined: 25mg/kg, i.p. and 50mg/kg, i.p. (once a day for 28 days). Two different timings of administration were also examined: early treatment (initial dose given three days after tumor transplantation) and late treatment (initial dose given 31 days after tumor transplantation). In order to evaluate the effects of the treatment, the relative tumor-growth ratio (T/C-ratio) was determined and histopathological estimates were made. The two-dimensional tumor measurements taken periodically were transformed into estimates of tumor weight using the formula ((s^2x1)/2,s: short legth, 1: long length). Histopathological changes of treatment were estimated by the degree of histological degeneration proposed at National Cancer Research Institute (Shimosato's classification). The histological criteria for the evaluation of treatment were classified from grade I to grade IV; any degeneration more than grade III was considered positive. Based on T/C-ratio evaluation, significant effects were obtained only in the early treatment groups; no remarkable changes were noted in the late treatment groups. Based on histopathological evaluation, significant effects were noted only in the early treatment groups. In the groups treated with a combination of BG and irradiation, a single irradiated dose (10Gy) was given 31 days after tumor transplantation; after that, BG was given 25 mg/kg, i.p, and 50mg/kg, i.p. once a day for 55 days. Based on the T/C-ratio evaluation, significant effects were noted in the combination treatment groups, but no remarkable histological degeneration was noted. The results suggest that there is a correlation between the results noted in the T/C-ratio evaluation and in histological evaluation in the groups receiving early BG treatment. As regards the mature tumors, significant effects on the T/C-ratio and the long-term survival of hosts (nude mice) were also noted in our treatment.