Chemotherapy of transplanted adenocarcinomas of the colon in mice.

Transplantable adenocarcinomas of the colon in mice have been developed from primary tumors induced by 1,2-dimethylhydrazine. Two such transplant lines, MAC-13 and MAC-15, have been used to assess the possible value of this type of tumor in chemotherapy screening. A protocol has been established and 11 standard drugs were tested against the two lines. Both tumors show sensitivity which is remarkably similar to that of human large bowel cancer, and MAC-13 would have correctly predicted the activity in man for ten of the 11 drugs. Quantitatively, CCNU, methyl-CCNU, and cyclophamide were the most effective drugs. A comparison of the predictive efficiencies of L1210 leukemia, B16 melanoma, and these new tumors as screening systems for colorectal cancer is made and discussed.