Chemotherapy studies in autochthonous rat tumors. Forestomach and bladder cancer.

Acetoxymethyl-methyl-nitrosamine (AMMN) induced only carcinomas of the forestomach in female Sprague-Dawley rats after an induction time of about 100 days when applied orally twice weekly in single doses (d) of 3.5 mg/kg body weight, Butyl-butanol-nitrosamine (BBN) selectively produced bladder tumors in female Sprague-Dawley rats after about 280 days when given in daily oral single doses (d) of 10 mg/kg body weight. The reactions of a total of 520 rats with chemically induced tumors were tested using 4-drug combination chemotherapy with different equitoxic doses of Adriamycin (Adm), Methotrexate (Mtx), 5-Fluorouracil (5-FU) and Bleomycin (Blm). The influences of combined therapy on mean sruvival time, tumor weight, histology of tumors, and adverse side effects of therapy are herein described. The results showed to be tumorspecific. In addition, the comparability of experimental chemotherapy in autochthonous rat tumors to clinical experience is discussed.