The effect of various chemotherapeutic agents given with mild hyperthermia on different types of tumours M. Takemoto A1, M. Kuroda A1, M. Urano A2, Y. Nishimura A3, S. Kawasaki A4, H. Kato A4, Y. Okumura A1, S. Akaki A1, S. Kanazawa A1, J. Asaumi A5, I. Joja A4, Y. Hiraki A1 A1 Department of Radiology, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan A2 Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, 1275 York St., New York, NY 10021, USA A3 Department of Radiology, Kinki University Medical School, Ohno-higashi, Osaka-sayama 599-8511, Japan A4 Faculty of Health Sciences, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan A5 Department of Oral and Maxillofacial Radiology, Okayama University Graduate School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan Abstract: It has been shown that hyperthermia can enhance the cytotoxicity of some chemotherapeutics. However, the most effective agent(s) at elevated temperatures have yet to be determined. A previous study suggests that the drug of choice at elevated temperatures may be different from that at the physiological temperature, and that the alkylating agents may be most effective at elevated temperatures. To further investigate these possibilities, the effect of chemotherapeutic agents were compared. These agents were cyclophosphamide, ifosfamide, melphalan, cis-diamminedichloroplatinum (II), 5-fluorouracil, mitomycin C and bleomycin. Three tumours (mammary carcinoma, osteosarcoma and squamous cell carcinoma) were used. They were transplanted into the feet of C3H/He mice. When tumours reached 65 mm3, a test agent was injected intraperitoneally. Tumours were immediately heated at 41.5°C for 30 min, and the tumour growth (TG) time was studied for each tumour. Using the TG times, the TG-50 (the time required for one-half of the total number of the treated tumours to reach the volume of 800 mm3 from 65 mm3) was calculated. Subsequently, the tumour growth delay time (GDT) and the thermal enhancement ratio (TER) were obtained. The GDT was the difference between the TG-50 of treated tumours and that of non-treated control tumours. The TER was the ratio of the GDT of a group treated with an agent at 41.5°C to that of a group treated with the agent at room temperature. Results showed that the top three effective agents tested at 41.5°C were solely alkylating agents--CY, IFO and L-PAM--for each kind of tumour. A GDT of cisplatin was smaller than those of the alkylating agents. The smallest TER, 1.1, was observed for 5-fluorouracil, which was given for mammary carcinoma, and for mitomycin C, which was given for squamous cell carcinoma. It could be concluded that the alkylating agents at elevated temperatures might be the drugs of choice for many types of tumours. The possible mechanisms of thermal enhancement associated with these agents are discussed. International Journal of Hyperthermia Volume 19, Number 2 / March 2003 193 - 203 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.