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

Background: why researchers are examining ozone alongside cancer treatment

Radiotherapy and chemotherapy remain central to cancer treatment, but their effectiveness can be limited by tumour hypoxia - low oxygen levels within tumour tissue - and by side effects on healthy tissue. Researchers have long looked for supportive approaches that might improve tissue oxygenation and help the body tolerate treatment. Ozone therapy, delivered through methods such as ozonated autohaemotherapy, has been studied for its effects on oxygen delivery, antioxidant defences and the immune response. This review set out to gather the existing laboratory, animal and clinical evidence on whether ozone might have a role as an adjuvant - a supportive addition - alongside conventional cancer treatment.

Study design: how the review was assembled

The paper is a narrative review rather than an experiment or a clinical trial. Its authors, led by Bernardino Clavo, drew together published in vitro (laboratory) studies, animal experiments and isolated clinical reports describing ozone used around the time of radiotherapy or chemotherapy. Rather than testing patients themselves, the authors summarised and interpreted what earlier studies had reported, and mapped where the evidence appeared strong, weak or missing.

Findings: what the laboratory, animal and clinical evidence shows

Across the sources reviewed, laboratory and animal studies suggested that ozone can influence processes relevant to cancer treatment - including tumour oxygenation, the balance between oxidative stress and antioxidant defences, and aspects of the immune response - and, in some models, appeared to complement the effects of radiotherapy and chemotherapy. The authors also pointed to isolated clinical reports, for example in the healing of tissue after tumour removal. They were careful to record, however, that the clinical evidence remained limited and preliminary, consisting largely of small reports rather than controlled trials.

What the authors concluded

The authors concluded that current findings point to a possible supportive role for ozone as an adjuvant during radiotherapy and/or chemotherapy, but that this potential is not yet proven. They emphasised that well-designed research, in particular randomised clinical trials, is required before ozone could be regarded as a useful adjuvant tool in cancer care. Their central question - whether further research is warranted - was answered in the affirmative.

Limitations of this study

As a narrative review, the paper reflects the studies its authors chose to include and does not follow the systematic, pre-registered search methods used in a systematic review or meta-analysis. Much of the supporting evidence came from laboratory and animal models, which do not always translate to people, and the clinical material was limited to small, uncontrolled reports. No conclusions about effectiveness or safety in patients can be drawn from this review alone.

This study reviews ozone as a possible adjuvant alongside conventional cancer treatment. It does not examine ozone as a treatment for cancer itself. Ozone therapy is a complementary approach and should always be discussed with your oncology team.