[In vitro sensitivity testing of human kidney tumors to cytostatic drugs with a rapid in vitro test]

We present a new modified in vitro culture assay for primary human renal cell carcinoma similar to the 'soft agar clonogenic assay'. However, the carrying out and expense of metrology are more simplified, allowing tumor-specific chemotherapeutic drug sensitivity testing under easier conditions. Twelve different samples of human renal carcinoma and one sample of a transitional cell carcinoma of the renal pelvis were tested for in vitro chemotherapy sensitivity using this modified colony-forming assay. The rate of tumor cells establishing in culture was 100%. Corresponding to clinical experience we observed a nearly complete resistance to the cytotoxic effects of standard chemotherapeutic agents at usual plasma concentrations in man. Only higher concentrated chemotherapeutic drugs showed in vitro therapeutic effects. The assay described here lasts about 7 days, which is beneficial from the clinical point of view. The modification of this in vitro chemotherapeutic drug treatment is unlimited for plasma concentration and duration of standard and experimental chemotherapeutic agents, drug combination and so on. So we have interesting scientific steps which could not have been undertaken under usual clinical-empirical conditions.