Ozone Therapy as Adjuvant for Cancer Treatment: Is Further Research Warranted?

Introduction. This article provides an overview of the potential use of ozone as an adjuvant during cancer treatment. Methods. We summarize the findings of the most relevant publications focused on this goal, and we include our related clinical experience. Results. Over several decades, prestigious journals have published in vitro studies on the capacity of ozone to induce direct damage on tumor cells and, as well, to enhance the effects of radiotherapy and chemotherapy. Indirect effects have been demonstrated in animal models: immune modulation by ozone alone and sensitizing effect of radiotherapy by concurrent ozone administration. The effects of ozone in modifying hemoglobin dissociation curve, 2,3-diphosphoglycerate levels, locoregional blood flow, and tumor hypoxia provide additional support for potential beneficial effects during cancer treatment. Unfortunately, only a few clinical studies are available. Finally, we describe some works and our experience supporting the potential role of local ozone therapy in treating delayed healing after tumor resection, to avoid delays in commencing radiotherapy and chemotherapy. Conclusions. In vitro and animal studies, as well as isolated clinical reports, suggest the potential role of ozone as an adjuvant during radiotherapy and/or chemotherapy. However, further research, such as randomized clinical trials, is required to demonstrate its potential usefulness as an adjuvant therapeutic tool.