German Clinical Trials Register

Acronym/abbreviation of the study

HISTOTHERM

URL of the study

No Entry

Brief summary in lay language

After completion of breast cancer treatment, the majority of affected women are are permanently cured. In some cases, however, the cancer returns in the area of the breast or the chest wall. In such cases, in order to make renewed radiotherapy as effective as possible and still tolerable, the radiation can be combined with heat therapy (hyperthermia). By locally heating the tissue to approx. 42 °C the effect of the radiation therapy on the tumor cells can be significantly improved, without causing increased damage to the healthy tissue. This means that a much lower radiation dose is required than with radiation therapy alone. While the efficacy and tolerability of this combination therapy has been shown in a number of clinical studies, knowledge about the mode of action in tissue is still very limited. Also, no specific characteristics of the tumor cells are yet identified that would indicate a good or poor response to therapy in advance of treatment. Treatment response and quality of life will be assessed in the study. Two central questions are: (1) Which processes happen in the tissue under the combination treatment of hyperthermia and low-dose radiotherapy? Of interest here is not only the reaction of the tumor cells themselves, but also the reaction of the surrounding connective tissue, blood vessels and the immune system. (2) Is it possible to identify characteristics of the tumor cells and the other tissues involved that can predict the success and tolerability of the treatment?

Brief summary in scientific language

The combination treatment of hyperthermia and hypofractionated radiotherapy is often the only sufficient treatment option for patients with superficially located, non-resectable breast cancer recurrences. Conventional re-irradiation is limited by the previous, often multiple radiotherapies. In a study by Notter et al 2020, combined treatment led to partial or complete tumor regression in the majority of patients (n=201), with minimal side effects. Hyperthermia around 42°C sensitizes tumor cells to radiation without causing cytotoxic effects in normal tissue. The cellular processes in tumor and stroma induced by the combination therapy are not known. Objectives of this study are to identify cellular mechanisms as well as predictive markers. The study will assess clinical and histological response to treatment and quality of life before, during and after therapy.