Invited commentary

Abstract

The use of heat to treat disease has existed as long as recorded history. Observations relevant to cancer show heat does the following: (1) selectively kills cells as a function of thermal dose (duration of exposure × degree of temperature elevation); (2) selectively kills S-phase and radiation-resistant cells; (3) partially inhibits DNA repair; (4) kills cells with a defective heat-shock response; and (5) is a stimulus for apoptosis. Tumor cells, therefore, are more vulnerable to heat than normal cells. The clinical application of hyperthermia, often in conjunction with chemotherapeutic agents, includes three general methods based on the extent of the body treated. Localized hyperthermia utilizes heat for primary and recurrent tumors and appears most successful for head and neck tumors. Regional or isolated organ/limb hyperthermia utilizes heat restricted to specific regions of the body. Response has been documented in select patients for tumors of the limbs, liver, pancreas, esophagus, gastrointestinal tract, colon, and rectum. Whole-body hyperthermia uses methods that heat the entire body to a target core temperature of approximately 42 degrees centigrade to treat metastatic disease. Effectiveness is still controversial because of the difficulty in administering and monitoring systemic hyperthermia and limited experience.