[Resistance testing of cytostatic agents on human tumors (author's transl)].

An in vitro short term incubation of human tumors with different cytostatic agents and their corresponding radioactive precursors of cell metabolism allows detection of those drugs which are inefficacious on the examined tumor. The pretherapeutical knowledge of those substances keeps the patient from unnecessary and damaging cytotoxic treatment. The in vitro and in vivo correlation of this technique was tested on 3 different groups of tumor patients: 1. Chemotherapeutically treated tumor patients with primary or secondary induced resistance against the applied cytostatic agents: all substances which clinically did not influence the tumor growth at the moment of the test also were inefficient in the in vitro test system. 2. Tumor patients who were treated according to a clinical therapy regimen contrary to the results of the in vitro testing: corresponding to the test, no influence on tumor growth was seen. 3. Tumor patients who were treated according to the results of the resistance test: after 8 weeks observation none of these patients had any signs of tumor progression.