Interactions of mild hyperthermia, cisplatin and split dose irradiation in human ovarian carcinoma cells.

ABSTRACT

PURPOSE: Human ovarian cancer cells were evaluated to determine whether combination treatment with mild hyperthermia and cisplatin could inhibit repair of sublethal radiation damage. MATERIALS AND METHODS: Human ovarian carcinoma cell lines A2780S (parental line) and A2780CP (cisplatin resistant variant) were used in this study. Cisplatin at concentrations of 1 or 3 microg/ml was given concomitantly with 1 h of heating at 40 degrees C either immediately before or after irradiation. Survival 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 parental cell line. CONCLUSIONS: The data show that combined treatment of cisplatin and hyperthermia may have clinical efficacy at cisplatin concentrations and hyperthermia temperatures which by themselves have little to no effect.