Comparative study on nude mice isotope assay (NM-IA) and subrenal capsule assay (SRCA) sensitivity tests of anticancer agents

Abstract

A comparative study on nude mice isotope assay (NM-IA) and subrenal capsule assay (SRCA) was done to evaluate the usefulness of in vivo assays for predicting individual tumor sensitivity against anticancer agents. Sixty-one fresh tumor specimens collected at surgery, under sterile conditions, were examined. Mitomycin C (MMC), 5-fluorouracil (5-FU), cyclophosphamide (CPM), adriamycin (ADM) and cis-DDPlatinum (CDDP) were used in both assays. In NM-IA, the tumor sensitivity was determined by the amount of 3H-thymidine incorporated into the tumor which had been implanted into subcutaneous spaces of BALB/c nude mice. In the SRCA, the relative increase in weight of the tumor implanted into the subrenal capsular space of ddY mice was determined and measurements made to evaluate the chemosensitivity. Evaluability rates of the trials were 86.9 per cent with both assays and the response rates were 35.8 per cent in NM-IA and 34.0 per cent in SRCA, respectively. Against MMC, 5-FU, CPM, ADM and CDDP, overall consistency rates between the two assays were 77.8 per cent, 88.6 per cent, 72.7 per cent, 81.8 per cent and 68.2 per cent, respectively. In 8 of these 53 evaluated assays, correlations between the results of assays and clinical effects were examined and overall predictive accuracy rates were 87.5 per cent with both assays. Significant differences between these two in vivo chemosensitivity tests were not evident.