2020, Witzke, Katharina, Seebauer, Christian, Jesse, Katja, Kwiatek, Elisa, Berner, Julia, Semmler, Marie‐Luise, Boeckmann, Lars, Emmert, Steffen, Weltmann, Klaus‐Dieter, Metelmann, Hans‐Robert, Bekeschus, Sander

The prognosis of patients suffering from advanced-stage head and neck squamous cell carcinoma (HNSCC) remains poor. Medical gas plasma therapy receives growing attention as a novel anticancer modality. Our recent prospective observational study on HNSCC patients suffering from contaminated tumor ulcerations without lasting remission after first-line anticancer therapy showed remarkable efficacy of gas plasma treatment, with the ulcerated tumor surface decreasing by up to 80%. However, tumor growth relapsed, and this biphasic response may be a consequence of immunological and molecular changes in the tumor microenvironment that could be caused by (a) immunosuppression, (b) tumor cell adaption, (c) loss of microbe-induced immunostimulation, and/or (d) stromal cell adaption. These considerations may be vital for the design of clinical plasma trials in the future.