Chemosensitivity testing of human lung cancer tissues using the succinate dehydrogenase inhibition test

We examined the chemosensitivity of 57 primary lung cancer specimens to 9 antitumor drugs, using the succinate dehydrogenase inhibition (SDI) test. Average succinate dehydrogenase (SD) activity was reduced to less than 50% by cis-diaminedichloroplatinum (II) (DDP), cyclophosphamide (CPA), carboquone (CQ), mitomycin C (MMC) and adriamycin (ADM). The lung cancer cells were relatively resistant to pepleomycin (PEP), 5-fluorouracil (5FU), vincristine (VCR) and vindesine (VDS). Small cell lung cancers, or early stage lung cancers, tended to be more sensitive to these antitumor drugs. However, differences in sensitivity with respect to either histology, staging or degree of differentiation were not statistically significant. Correlation of SD activity between 2 drugs was high among those which inhibit DNA synthesis (DDP, CPA, CQ or MMC), or between VCR and VDS (inhibitor of mitosis), however, the correlation between VDS and CPA, CQ or DDP was weak. The SDI test is a simple in vitro method readily available to aid in selecting drugs to treat patients with lung cancer.