Cytotoxicity of dimethyl sulfoxide and antineoplastic combinations against human tumors.

Five human tumor reference cell lines were tested in vitro against 0 percent, 5 percent, and 10 percent DMSO; four antineoplastic agents; and combinations of 5 percent or 10 percent DMSO plus each antineoplastic agent. Synergistic cytotoxicity between DMSO and antineoplastic agents against each cell line were demonstrated. We have concluded that delivery of standard doses of antineoplastic agents in 5 percent or 10 percent DMSO may be useful in the treatment of some tumors because of the marked increase in tumoricidal effect seen with some DMSO and drug combinations. Alternatively, lower doses of antineoplastic agents might be delivered in DMSO, producing the same cytotoxic effect as a full dose of drug without DMSO but with less systemic toxicity.