Comparison of tumor response in nude mice and in the patients.

In 34 tumors of different origin 50 comparisons between the tumor response in the patients and in nude mice were performed. Combination chemotherapy was more successful than single agent chemotherapy. Out of the 25 combinations given, 9 (36%) effected a remission in comparison to 4 out of 25 (16%) after single agent chemotherapy. 13 patients got a remission which was found in 12 cases in the nude mouse, too. 37 patients did not respond to treatment and the same result was found in 36 cases in the nude mouse system. Xenografts gave a correct prediction for resistance in 97% and for tumor response in 92%. Despite great efforts to obtain a large number of comparisons, only 22 test results were available before the patients needed chemotherapy. In 13 cases chemotherapy was done simultaneously in the patient and in the nude mouse system. In 15 cases the patients were treated first. The xenograft system will not have practical significance in determining the treatment of the patients. Limitations are the duration of the testing, the testing rate of about 50% and the charges for nude mice. However, the highly correct prediction rates for tumor sensitivity and resistance validates human tumor xenografts as tumor models to test new drugs and combinations.