Preclinical Hyperthermia in Human Tumors: Introductory Remarks

Abstract

Hyperthermia is on the way to becoming a tool for the clinical treatment of cancer. For several reasons, discussed elsewhere (Engelhardt 1985, 1987; Hahn 1982), hyperthermia is going to be used preferentially in combination with radiation and cytotoxic chemotherapy. In developing the clinical approach one has to be aware of a huge number of complex interactions between the patient, the tumor, the heat, the irradiation, and the drugs. From the basic research data about heat effects and from our experience in clinical oncology we can predict a long list of circumstances that will modify the effect of heat applied alone or as part of a combined modality:

• Patient

  • Performance status

  • Age

  • Sex

  • Other disease

  • Supportive care

• Tumor

  • Type/histology/grading

  • Burden/stage

  • Size of lesions

  • Site of lesion(s)

  • Sensitivity

  • Heterogeneity

  • clonal

  • cell cycle

  • environmental

• Heat

  • Heating rate

  • Maximum level

  • Duration

  • Timing

  • Fractionation

  • Thermotolerance

  • Application technique

• Radiation

  • Type

  • Dosage

  • Fractionation

• Drug

  • Type of action

  • Dosage

  • Pharmacokinetic

  • Combinations

  • Schedule of administration

  • Route of administration

Most of our knowledge about heat effects stems from laboratory work done in cell lines of murine (or other mammalian) origin. Further experience has been gained with animal tumors “treated” after transplantation or, more seldom, in situ, i. e., at the site of origin.