There are plenty of studies available online that you can consult to confirm its efficiency.
Findings on the following studies correspond with our approach on the subject:
Brown, N. S., & Bicknell, R. (2001). Hypoxia and oxidative stress in breast cancer Oxidative stress-its effects on the growth, metastatic potential and response to therapy of breast cancer. Breast cancer research, 3(5), 323. https://breast-cancer-research.biomedcentral.com/articles/10.1186/bcr315
Fang, J., Seki, T., & Maeda, H. (2009). Therapeutic strategies by modulating oxygen stress in cancer and inflammation. Advanced drug delivery reviews, 61(4), 290-302.
Masaru Sagai, Velio Bocci. (2011) Mechanisms of Action Involved in Ozone Therapy: Is healing induced via a mild oxidative stress? Medical Gas Research.
Matés, J. M., & Sánchez-Jiménez, F. M. (2000). Role of reactive oxygen species in apoptosis: implications for cancer therapy. The international journal of biochemistry & cell biology, 32(2), 157-170. http://www.sciencedirect.com/science/article/pii/S1357272599000886
Vera-Ramirez,L., et al. (2011) Free radicals in breast carcinogenesis, breast cancer progression and cancer stem cells. Biological bases to develop oxidative-based therapies. Critical Reviews in Oncology/Hematology. http://www.sciencedirect.com/science/article/pii/S1040842811000059