[Analysis of the chemosensitivity test by subrenal capsule assay]

The antitumor activity of several chemotherapeutic agents against a total of 30 clinical samples obtained from 30 human tumors from the esophagus (12), stomach (10), colorectum (6) and lung (2), were tested by subrenal capsule assay (SRCA) using normal immuno-competent BDF, mice. The antitumor activity was evaluated by changes in both tumor size (delta TS method) and tumor growth inhibition rate (TGIR method). Among the 30 tumors, 15 were also tested by human tumor clonogenic assay (HTCA) and the results obtained in the two assays were compared. In the SRCA, adequate growth of the tumor in the control group for evaluation of the response of the treated group was obtained from 27 out of 30 tumors (90%). With activity criteria set at delta TS less than or equal to -1.0 dmm and TGIR greater than or equal to 50%, 41% of the drugs tested were active in delta TS while 27% were active in TGIR. When relationships between antitumor activities evaluated by delta TS and TGIR was compared, both activities were well correlated (r = -0.64). Correlations between tumor responses in the HTCA and in the SRCA were tested in 6 tumors treated with 20 drugs. The overall accuracy was 60% by the TGIR method and 70% by the delta TS method, respectively.