Ozone Therapy in Cancer Treatment: State of the Art

Background: why researchers looked at ozone alongside cancer care

Cancer remains one of the most difficult conditions to treat, and interest has grown in approaches that might sit alongside conventional therapy such as surgery, chemotherapy and radiotherapy. Ozone has drawn attention because, at controlled doses, it appears to influence oxidative stress, antioxidant defences and the oxygen supply to tissues. Because many tumours are poorly oxygenated - a state linked to resistance to radiotherapy and some drugs - some investigators have asked whether ozone's effect on oxygenation and cellular metabolism could have any supportive role. This review was written to gather what was known at the time and to judge how far the evidence had progressed.

Study design: a review drawing on laboratory, animal and early clinical work

The article is a narrative, state-of-the-art review rather than an experiment or a controlled trial. The authors summarised the biological rationale for ozone and pulled together findings from three kinds of source: laboratory (in vitro) studies on cells, experiments in animal tumour models, and a small amount of early clinical work, including a trial in patients with prostate cancer. It did not use a systematic search protocol or pool the results statistically; instead it set out the mechanisms proposed for ozone and described the evidence available in each of these areas.

Findings: modest signals reported, alongside clear gaps

The review reported that ozone, used carefully, produced measurable biological effects and that some studies suggested a possible adjuvant role when combined with chemotherapy or radiotherapy, together with signs of an antimetastatic effect in experimental models. The authors described these observations as promising but preliminary. Much of the supporting data came from cell and animal work, with only limited human evidence, and the review did not present ozone as an established or stand-alone anticancer treatment.

What the authors concluded

The authors concluded that, despite the positive biological effects observed and ozone's potential usefulness as an adjuvant in chemo-radiotherapy and its reported antimetastatic effect, further investigation was necessary before ozone therapy could be considered a complementary therapy for cancer. In other words, they framed the field as early-stage and in need of well-designed clinical studies rather than settled.

Limitations of this review

As a narrative review, the article did not follow a systematic method, so relevant studies may have been missed and the selection of evidence reflects the authors' judgement. Most of the underlying data was preclinical - drawn from cells and animals - and the human evidence was small and largely uncontrolled, which limits how far the conclusions can be applied to patients. The review was published in 2008, so it does not capture research produced since. This article reviews early and largely preclinical evidence on ozone as a possible adjuvant alongside conventional cancer treatment. It does not establish ozone as a treatment or cure for cancer. Ozone therapy is a complementary approach and should always be discussed with your oncology team.