Byline: Neena. Shetake, B. Pandey
Hyperthermia is the most ancient cancer treatment modality used much before even the discoveries of conventional therapeutic modalities such as radiotherapy. Since then, as a cancer therapeutic modality, hyperthermia has seen several advancements, but an upsetting decline in its recognition in last few decades. Currently, majority of the laboratories working in the research field are engaged in developing combinatorial strategies for hyperthermia along with radiation/anticancer agents. For the targeted delivery of therapeutic agents, several nano-formulations have been developed. In recent years, magnetic nanoparticle-based 'nanothermotherapy' is getting the attention of researchers. Unfortunately, despite several successful clinical studies, hyperthermia could not get its due acclaim in cancer therapeutics. In the last few decades, mechanistic insights achieved using cutting-edge technologies opened several therapeutic avenues of many diseases including cancer. However, for many reasons, hyperthermia scientists could not match the pace to tap the knowledge for deeper mechanistic insights. Key questions, such as epigenetic changes, role of immune cells/abscopal effects in hyperthermia, and thermo resistance, still needs to be addressed in depth. It is noteworthy to mention that a deeper mechanistic insight shall contribute immensely in hyperthermia-based cancer therapy not only through overcoming thermoresistance but also through assisting in developing novel thermosensitizers and thermotherapy protocols.
Hyperthermia is a process of raising the body temperature, either locally or for the whole body for medicinal purposes. The glorious history of hyperthermia oncology began way back in 1779 by de Kizowitz in France, showing the inhibition of tumor growth by high fever caused by malaria. After surgery, this may be probably the first cancer treatment modality. However, systematic school of hyperthermia-based cancer treatment was developed in 1893 by William B. Coley, a bone surgeon in New York Memorial Cancer Hospital (now the Memorial Sloan-Kettering), who treated cancer patients using bacterial antitumor pyrogen also called 'Coley toxin'., Later in 1898, as the first regional hyperthermia, the Swedish gynecologist, Wester Mark treated seven cervical cancer patients by running hot water through an intracavitary spiral tube, which resulted in an excellent clinical response. After that by 1975, hyperthermia experienced a considerable progress and acceptance in oncologists with many advancements such as radiofrequency for hyperthermia application and techniques for whole-body hyperthermia and regional hyperthermic perfusion.
An early knowledge about the systemic effects of hyperthermia in tumor control and active involvement of clinicians helped in easy acceptability of the technique in cancer therapy. The long journey of clinical hyperthermia oncology is full of many leaps, but a fall has been observed in the last two decades. The drift of oncologists from hyperthermia could be linked with many technological, clinical, and nonclinical reasons. One of the reasons is believed to be due to lack of updated mechanistic insight about the therapy. On the other hand, the technological advancements in the field of radio-/chemotherapy matched with subterranean molecular insights, which overshadowed the merits/success laurels of hyperthermia.
Mechanistic insight of hyperthermia is enriched with several early concepts of its action at cellular level. Later on, differential action of hyperthermia on...