[Growth chamber assay, a chemosensitivity test to eliminate normal stromal cells]

Chemosensitivity test using growth chamber (GC) was executed on 7 human and murine cell lines, 16 human tumor xenografts and 60 fresh surgical specimens. Dissociated tumor cells suspended in tumor growth medium were plated into GC and incubated with a various concentration of mitomycin C (MMC), adriamycin (ADM), cisplatin (DDP) and 5-fluorouracil (5-FU). After an incubation of 7 days, the activity of hexosaminidase was detected with EIA reader. The antitumor spectra detected by GC assay was essentially identical to those of in vivo nude mouse system, although no evaluable optical density was obtained in normal stromal cell lines. The optimal cutoff concentration of each drug to predict in vivo results was estimated to be 10 micrograms/ml for MMC, 15 micrograms/ml for DDP and 5-FU, and 0.7 microgram/ml for ADM. The predictable accuracy of GC assay on human tumor xenografts was 82.0%. Fifty five clinical specimens were evaluable from 60 cases, and the efficacy rates of MMC, ADM, DDP and 5-FU were 13.3, 25.0, 25.0, and 12.5%, respectively, and the overall accuracy for clinical effects was 72.1%. This assay was thought to be useful for clinical specimens in particular with a large amount of stromal cells.