[Experimental and clinical studies on chemosensitivity tests of anticancer agents by human tumor clonogenic assay]

In vitro chemosensitivity tests of anticancer agents for 119 fresh human tumors were performed by the human tumor clonogenic assay (HTCA) technique and the following results were obtained. Colony growth (greater than or equal to 5 colonies/dish) was observed in 35 of 50 gastric cancers (70.0%), 10 of 17 colon cancers (58.8%), 13 of 14 breast cancers (92.9%), two of six esophageal cancers (33.3%), three of six sarcomas (50.0%), three of 16 hematological malignancies (18.8%) and seven of 10 other tumors (70.0%). Colony growth rate differed according to the type of tumor. Fifty four tumors formed adequate colony growth (greater than or equal to 30 colonies/dish) for the chemosensitivity test. Mitomycin C (MMC), 5-Fluorouracil (5-FU), 4-hydroperoxy cyclophosphamide (CPM), Adriamycin (ADM), Cis-dichlorodiammineplatinum (CDDP), and alpha-interferon (IFN-alpha) were tested. The average positive rates of MMC, 5-FU, CPM, CDDP, and IFN-alpha were 26.9, 21.6, 10.5, 26.9, 36.8, and 23.3% respectively for all the tumors tested. In gastric cancer, the positive rates of MMC and 5-FU were 24.0 and 21.6% respectively, whereas the rates were 33.3 and 33.3% in colon cancer and 18.2 and 16.7% in breast cancer respectively. Each tumor exhibited its own chemosensitivity rates against various anticancer agents. Eighteen of the results obtained were comparable to clinical responses. The true positive rate was 50.0% (2/4) and the true negative rate 92.9% (13/14). A statistically significant correlation was observed between the results of HTCA and clinical responses (chi 2 test, p less than 0.05). The combined effects of IFN-alpha and MMC were surveyed against 20 gastroenterological tumors. Nine tumors exhibited synergistic effect, though antagonistic effect was observed in three tumors. The effects of oxygen tension (2%, 5%, 20%) on colony growth were investigated. The greatest development of colonies occurred at an oxygen of five percent, which is considered to be physiological oxygen tension, and statistically significant increases of plating efficiencies at 5% O2 as compared to those at 20% O2 were observed (t-test, p less than 0.025).