Cumulative results of chemosensitivity tests for antitumor agents in Japan. Japan Research Society for Appropriate Cancer Chemotherapy.

The Japan Research Society for Appropriate Cancer Chemotherapy set out to summarize the present status of chemosensitivity testing for antitumor agents in Japan. Two different questionnaires were sent to 122 and 94 institutes, respectively, whilst responses were received from 87 (71.3%) and 41 (43%) institutes, respectively. The results showed that chemosensitivity tests were performed in 42 institutes where a total of 2 in vivo and 10 in vitro different assays were performed. Actual cases of chemosensitivity detected by the tests varied from 1 to 368 cases/year/institute with a median of 15 cases and mean +/- standard deviation of 48 +/- 65 cases. The total number of tested cases increased from 1,747 cases in 1993 to 1,934 cases in 1994 and to 2,147 cases in 1995, resulting in an average of 1,891 cases year. The assays used included the adenosine triphopsphate inhibition assay,/the collagen droplet embed drug response assay, the fluorescent dye assay, the growth chamber assay, the histoculture drug response assay, human tumor clonogenic assay, the MTT assay (SDI test), the nuclear damage assay, the nude mouse model, the subrenal capsule assay and the thymidine incorporation assay (scintillation assay). The correlation of in vitro and in vivo results revealed 215 true positive (S/S), 246 false positive (S/R), 45 false negative (R/S) and 595 true negative (R/R) cases, resulting in rates of 47% for true positives and 93% for true negatives, with a 74% accuracy. We concluded that chemosensitivity testing is widely applied in this country and has a high accurate predictive value for advanced carcinomas.