INTERACTIONS OF MILD HYPERTHERMIA, CISPLATIN AND SPLIT-DOSE IRRADIATION IN HUMAN OVARIAN-CARCINOMA CELLS

Purpose: Human ovarian cancer cells were evaluated to determine whethe r combination treatment with mild hyperthermia and cisplatin could inh ibit repair of sublethal radiation damage, Materials and methods: Huma n ovarian carcinoma cell lines A2780S (parental line) and A2780CP (cis platin resistant variant) were used in this study. Cisplatin at concen trations of 1 or 3 mu g/ml was given concomitantly with Ih of heating at 40 degrees C either immediately before or after irradiation. Surviv al was determined using a colony-forming assay. Results: Neither mild hyperthermia nor cisplatin treatments alone affected sublethal damage repair. The combined treatment showed an effect in both cell lines and was treatment sequence-dependent. The effect was greater in the paren tal cell line. Conclusions: The data show that combined treatment of c isplatin and hyperthermia may have clinical efficacy at cisplatin conc entrations and hyperthermia temperatures which by themselves have litt le to no effect.