Abstract
(1) Background: The continuous improvement in cancer treatment has led to improvement in patients’ survival and a subsequent increase in the number of cancer survivors living with adverse side effects of cancer treatments, sometimes with a high and adverse impact on their health-related quality of life (HRQOL). Side effects of cancer treatments are frequently associated with chronic status of oxidative stress, inflammation, and/or ischemia. The potential for ozone treatment to modulate those processes and improve some of those adverse effects has previously been described. The aim of this study was to evaluate the effect of ozone treatment on the HRQOL and grade of toxicity in symptomatic cancer survivors. (2) Methods: Before and after ozone treatment, we assessed (i) the HRQOL (according to the EQ-5D-5L questionnaire) and (ii) the grade of toxicity (according to the Common Terminology Criteria for Adverse Events of the National Cancer Institute of EEUU (CTCAE v.5.0)) in 26 cancer survivors with chronic side effects of radiotherapy and chemotherapy. (3) Results: There was a significant (p < 0.001) improvement in the EQ-5D-5L index as per the self-reported outcome evaluation of patients’ health status. All the dimensions of the EQ-5D-5L questionnaire (mobility, self-care, activities, pain/discomfort, and anxiety/depression) and the self-evaluation of the health status using the visual analog scale were significantly improved (p < 0.05). The grade of toxicity was also significantly decreased (p < 0.001). (4) Conclusions: In cancer survivors with chronic side effects of cancer treatment, ozone treatment can improve the grade of toxicity and the HRQOL. These results merit additional research. Further studies are ongoing.