A colon tumor model for anticancer agent evaluation

Colon tumors of mice were induced with 1, 2-dimethylhydrazine, N-nitroso-N-methylurethane, methylnitrosourea, and 4-methyl-N'-nitro-N-nitrosoguanidine. Of 82 transplantation attempts, four were successful, and the four tumors have been maintained as distinct tumor lines by subcutaneous transplantation. The tumors graded from II, adenocarcinoma, to IV, undifferentiated carcinoma. Volume-doubling times varied over a three-fold range, and metastatic potential ranged from 5 to about 100%. The tumors responded to treatment with some of the same agents found to be active in man. These included cyclophosphamide, 5-fluorouracil, and certain nitrosoureas. Preliminary evidence suggests that these tumor lines may be useful as experimental models.