Moderate Whole-body Hyperthermia in Tumor Patients: Influence on Circulating Tumor Cells, Tumor Response, Quality of Life, Fatigue, Psyche, Immune Response and Tumor Microenvironment

Moderate whole-body hyperthermia (mWBH) is considered to be a very well-tolerated treatment. It has been used in numerous naturopathic and oncological practices for decades. It is also being used more and more with an increasing number of non-oncological diseases. A recently published randomized study was able to prove a sustained positive effect of whole-body hyperthermia in patients with depressive episodes. However, there are no clinical studies that demonstrate the benefit of this measure with regard to oncological treatment. There is also a lack of clarity about the mechanism of action of mWBH. A positive modification of the tumor microenvironment (increased perfusion, reduced interstitial pressure) and an increased activation of tumor-killing immune cells could be shown preclinically - however, a clinical evaluation of these mechanisms has not yet taken place.

This randomized study aims to evaluate the effect of mWBH on the tumor response of patients suffering from advanced cancer. The aim of the study is to demonstrate an improvement in the therapy response rate three months after the end of therapy through the additional use of mWBH, measured by a positive influence on the change in the number of circulating tumor cells from the time before therapy to the time three months after the start of therapy.

Quality of life reported by patients, recorded by the FACT-G questionnaire, as well as psychological parameters, fatigue and various other parameters with regard to an increase in the effect on the tumor are evaluated as secondary endpoints. All patients also receive serial immune monitoring. For this purpose, blood samples are taken before therapy and several times during the course of the therapy, which are then evaluated with regard to cytokines, immunological proteins and specific subgroups of immune cells.

The patients all receive guideline-based therapy in line with current internal practice. In addition to standard therapy, patients are randomized 1:1 and, if randomized to the mWBH arm, receive an additional 3-4 mWBH sessions during their oncological treatment. A total of six different patient groups are included, all with palliative therapy intentions (patients with multiple metastatic malignant melanoma before initiation of immunotherapy (checkpoint blockade), patients with metastatic or inoperable pancreatic carcinoma for whom first-line chemotherapy with FOLFIRINOX is planned, patients before palliative radiation therapy for a hormone-receptor-positive breast cancer who have previously received palliative systemic therapy and have at least one other tumor lesion in addition to the one that was irradiated, patients with metastatic sarcoma in whom ablation of the metastases is not possible and who are receiving palliative first-line therapy using Doxorubicin is planned to treat patients with metastatic or loco-regionally recurrent HPV-associated squamous cell carcinoma of the head and neck region, cervix, anus or vulva, for whom no local therapy methods are possible and palliative first-line platinum therapy is planned, patients with metastatic castration-resistant prostate cancer with progressive disease after exhaustion of recommended therapy options for whom a therapeutic trial with lutetium-177-PSMA has been indicated). A total of at least 72 patients, stratified into the 6 subgroups mentioned above, should be evaluated in the study, who should receive three to four sessions of mWBH in addition to standard oncological treatment. In order to obtain the necessary minimum number of patients in all subgroups, the inclusion of 80 patients in the study is necessary with an expected drop-out rate of 10%.

In order to record the effect of mWBH on quality of life, fatigue and depression, study participants must fill out a questionnaire on quality of life, fatigue and depression before the start of therapy, at the end of treatment and two weeks after therapy. To evaluate the influence of mWBH on immune parameters, patients also receive additional blood samples before the start of therapy, at the end of therapy and at two follow-up times, which can normally be combined with routine blood samples.