In vitro short-term test to determine the resistance of human tumors to chemotherapy: Group for Sensitivity Testing of Tumors (KSST).

In a cooperative study conducted by nine different hospitals between 1975 and 1979, the results of a short-term test in vitro (cell suspension, incubation with cytostatics for three hours, determination of the effect of the cytostatic by means of radioactive precursors and liquid scintillation counter) were compared with the results of a cytostatic treatment in 155 patients. Seventy-two patients with ovarian carcinomas, 24 patients with bronchial carcinomas and 18 patients with mammary carcinomas were treated according to a uniform therapy schedule. The remaining patients were treated according to different therapy schedules. The results of the tests in vitro, in which the proliferation-dependent effect of 4-hydroperoxycyclophosphamide and doxorubicin hydrochloride was determined agree well with those of the clinical therapy. Tumors that responded only slightly to cytostatics in the test were also clinically progressive. Of the 76 tumors which proved to be resistant to doxorubicin (concentration 10(-1)mg/ml), 56 (73%) were clinically progressive, 2 tumors (2%) were in remission and 19 (25%) were unchanged. When the alternative evaluations (progression, remission) alone were compared with the test results, 56 (98%) of 57 tumors resistant in the test also proved to be clinically progressive.