[Experimental studies on combined chemotherapy with hyperthermia and ethanol for advanced esophageal cancer. I. In vitro effects of combined treatments on 3H-TdR uptake of FM3A cells by microculture method].

The combined effects of hyperthermia, bleomycin and ethanol were investigated using FM3A tumor cells in vitro. Cytotoxicity of the heating was found at temperatures higher than about 41 degrees C, and remarkably increased at 43 degrees C. Cytotoxicity of ethanol was found at concentrations higher than 4% v/v, and remarkably increased at 8% v/v. Cytotoxicity of bleomycin was dependent on the dose but not so remarkable as those of the heating and ethanol. Cytotoxic effects of bleomycin were enhanced by the combined use of hyperthermia (41-43 degrees C). It was also enhanced by the combined use of low concentrations of ethanol (2-4%). On the other hand, a synergistic effect in cytotoxicity was observed, when the moderate hyperthermia was combined with low concentrations of ethanol. In the combination of low concentrations of ethanol, moderate hyperthermia and bleomycin, marked increase of cytotoxicity was observed. A possible application of these findings to clinical therapy for advanced esophageal cancer was discussed.