Role of Hyperthermia in the Treatment of Gastrointestinal Cancers

Gastointestinal cancers continue to be a common health problem. Among gastrointestinal cancers, gastric and colorectal cancers are most common causes of cancer incidence and death worldwide. These are basically treated surgically, but multidisciplinary treatment is applied for locally advanced and recurrent cancers, and its main modality is chemoradiotherapy (CRT). Preoperative CRT is performed for locally advanced rectal cancer. On the other hand, postoperative CRT is viewed by many reports as the standard care for advanced stomach cancer in Western countries. Curative or preoperative CRT is a standard treatment for locally advanced esophageal cancer. There have been several reports on the combination of these with regional hyperthermia in which favorable therapeutic outcomes were achieved. Regarding hyperthermia, thermal enhancement by combination with radiation and various anticancer drugs has been reported in vitro and in vivo. Particularly, thermal enhancement by combination with novel anticancer drugs may lead to further improvement of the therapeutic outcome. For peritoneal dissemination of gastrointestinal cancers including stomach cancer, hyperthermic intraperitoneal chemotherapy has been shown to be effective, as expected. There is also a possibility of the combination of hyperthermia with immunotherapy. It is necessary to elucidate the mechanism of thermal enhancement and demonstrate the efficacy of hyperthermia by performing an appropriate clinical study.