Comparison between succinate dehydrogenase inhibition test and subrenal capsule assay for chemosensitivity testing.

The chemosensitivity result of the succinate dehydrogenase inhibition (SDI) test was compared with that of the subrenal capsule (SRC) assay in 23 human tumor tissues exposed to adriamycin (ADM), mitomycin C (MMC), cisplatin (DDP) and 5-fluorouracil (5-FU). The chemosensitivity was considered as positive when the succinate dehydrogenase (SD) activity of the drug-exposed cells was decreased to below 50% of that of control cells on day 3 in the SDI test, and the tumor size on day 6 was decreased to below -10% of that on day 0 in the SRC assay. Correlation rates between the decrease of SD activity in the SDI test and the decrease of tumor size in the SRC assay, using 23 evaluable cases in both assays, were r = 0.717 for ADM, r = 0.699 for MMC, r = 0.796 for DDP and r = 0.735 for 5-FU. The correlations of the chemosensitivity results were 73.9% for ADM, 73.9% for MMC, 82.6% for DDP and 60.9% for 5-FU. A positive correlation was noted between the in vitro and in vivo chemosensitivity results. This SDI test can serve as an effective tool for chemosensitivity testing.