[Chemosensitivity of adriamycin, mitomycin C, and bleomycin with in vitro colony assay]

In vitro colony assay was used to examine the sensitivities of adriamycin (ADM), mitomycin C (MMC), and bleomycin (BLM), and the effects of a prior chemotherapy on in vitro chemosensitivities of the drugs. One hundred forty-seven tumor specimens from 106 patients with various malignancies were placed in culture. Seventy tumors (56.0%) from 125 evaluable specimens which had histologically or cytologically confirmed to be malignant, and were plated at 5 x 10(5) cells/plate formed more than 30 colonies/plate enough for sensitivity assays. The results of in vitro sensitivities of the drugs were nearly similar to those reported in the clinical trials. The in vitro antitumor activity of BLM was noted in 3 (21.4%) of 14 patients with ovarian cancer, therefore the results suggest that the assay is useful to select effective drugs against tumors in which phase II study has never been performed. In vitro sensitivity of BLM was markedly reduced by a prior chemotherapy containing the same drug (p less than 0.05), and prior therapeutic ADM exposure also reduced in vitro activity of the drug, whereas there was no significant influence on in vitro activity of MMC. These results indicate the usefulness of the in vitro colony assay for predicting clinical antitumor activities of ADM, MMC, and BLM.