[Experimental and clinical studies on a sensitivity test of anticancer agents by 3H-thymidine autoradiography using a human malignant tumor transplanted to nude mice].

The 3H-thymidine uptake of human xenografts transplanted in nude mice and treated with various anticancer agents was studied by autoradiography and compared with the histological changes on the same specimen. One hundred and four human malignant tumors were transplanted into nude mice and treated with intraperitoneal administration of Mitomycin C (MMC) (3mg/kg), 5-Fluorouracil (5-FU) (25mg/kg X 3) and Cyclophosphamide (CPM) (80mg/kg), of which 97 cases were investigated. Autoradiographical evaluation was expressed as the inhibition rate of labeling index of the treated specimen in comparison with that of the control. Histological change was judged by Ohboshi and Shimosato's criteria. The rate of positive sensitivity was 65.5% in MMC, 34.9% in 5-FU and 51.8% in CPM by autoradiographical evaluation, while by histological evaluation 18.9%, 14.6% and 16.9%, respectively. From these results, it may be speculated that the autoradiographical evaluation of the tumor sensitivity against anticancer agents is more sensitive than the histological evaluation. As to MMC and CPM, statistically significant correlations were demonstrated between the results of this method and those of the experimental chemotherapy in accordance with the Battelle Columbus Laboratories Protocol using human malignant tumors serially transplanted into nude mice.