Sensitivity tests of tumors to cytostatic agents. II. Investigation on human tumors.

Certain substances which influenced nucleic acid metabolism were found to have about the same cytostatic activity on human cells when measured in tissue culture experiments (cell numbers) or in short-term cultures (3-H-uridine incorporation in cell suspensions). By treatment with a dose of cytostatics corresponding to 10 times therapeutic dose, chemosensitive tumors can be distinguished from non-responsive tumors. By using this in vitro test system to investigate the sensitivities of 100 human tumors, it is shown that 28 of these tumors were responsive to adriamycin, daunomycin and Actinomycin D. Good agreement was observed between these in vitro results and the literature data on clinical therapy using these particular substances.