Hyperthermia combined with chemotherapy - Biological rationale, clinical application, and treatment results

There is substantial evidence from preclinical data that the antitumor cyto toxicity of selected chemotherapeutic agents either alone or combined with radiation can be enhanced by appropriate heat exposure (40-44 degrees C) of cells or tumor tissues. Based upon these results the integration of hypert hermia as an additional treatment modality, given simultaneously with syste mic chemotherapy or in combination with radiochemotherapy, is currently tes ted at the clinic. Regional hyperthermia combined with chemotherapy or radi ochemotherapy showed impressive results (phase II studies) at clinical rele vant temperatures in locally advanced tumors of different entities in terms of objective response rate, local tumor control and relapse-free survival. Clinical protocols of well-designed phase III trials on combined treatment modalities integrating hyperthermia are rather limited but for some tumors confirm its clinical benefit. In general, the clinical approach to use hyp erthermia has gained much more interest within in the field of medical onco logy. One of the major reason is the substantial technical improvements mad e with the available commercial equipment for local or regional heating, es pecially in case of deep-seated lesions or systemic heating. Further testin g of the potential of hyperthermia combined with chemotherapy or radiochemo therapy in prospective randomized trials are warranted. At this time, hyper thermia as an adjunct to conventional treatment strategies is recommended i n the setting of clinical protocols. The results of prospective trials shou ld answer the question for which types of local advanced or metastatic tumo rs hyperthermia becomes standard as part of a multi-modal treatment strateg y.