Although a new study of hyperbaric oxygen therapy in JAMA Oncology has been “ anxiously awaited” by breast radiation oncologists, the trial does not provide the smoking gun evidence that would justify its routine use, according to experts.
Here’s a snapshot of the current state of affairs regarding hyperbaric oxygen therapy in breast radiation oncology.
What Is Hyperbaric Oxygen Therapy?
Hyperbaric oxygen therapy is a medical procedure aimed at reducing the late toxic effects of breast irradiation, including pain, fibrosis, and edema. Patients breathe pure oxygen at greater than atmospheric pressure in a specialized chamber or room. The process leads to increased partial pressures of oxygen in blood and tissues, which can help form new blood vessels and repair damaged irradiated tissue.
What Is the Current State of Play?
In 2021, the US Food and Drug Administration (FDA) cleared the therapy for a variety of disorders, including radiation injuries. Some health insurers may cover the procedure as well.
Still, the FDA has cautioned clinicians “to be wary of unproven claims of effect,” University of Toronto radiation oncologist Ezra Hahn, MD, and colleagues Aron Popovtzer, MD, and Benjamin W. Corn, MD, said in a JAMA Oncology editorial.
While the procedure is “seldom used by many in practice,” there is growing industry for the procedure. More than 1000 facilities in the United States offer hyperbaric oxygen therapy, but only about 15% are accredited by the Undersea and Hyperbaric Medical Society, which may signal misuse of the procedure.
Does the Latest Study Clarify Whether This Therapy Works?
The most recent evidence on hyperbaric oxygen therapy comes from a single-institution, randomized trial from the Netherlands, dubbed HONEY. In the trial, 189 women who experienced late toxic effects following adjuvant breast radiation were randomized 2:1 to hyperbaric oxygen therapy or a control arm. Of the 125 women offered hyperbaric oxygen therapy, only 25% (31 patients) accepted and completed treatment; those who declined received usual follow-up care.
Among women who completed hyperbaric oxygen therapy, 32% (10 of 31) reported moderate or severe pain at follow-up vs 75% of controls — a 66% reduction. Similarly, 17% of women who completed hyperbaric oxygen therapy reported moderate or severe fibrosis at follow-up vs 86% among the hypothetical treatment-completing controls — an 86% reduction. However, the authors did not observe a significant effect of hyperbaric oxygen therapy on breast edema, movement restriction, or overall quality of life.
The authors also included an intention-to-treat analysis, which included patients who declined hyperbaric oxygen therapy as part of the intervention group. This analysis estimated clinical outcomes among patients who had the intervention available to them, with some taking advantage and others not.
Overall, hyperbaric oxygen therapy “seems effective for reducing pain and fibrosis in women with late local toxic effects after breast irradiation,” concluded investigators led by Dieuwke R. Mink van der Molen, PhD, a researcher at the University Medical Centre Utrecht, the Netherlands. However, most patients offered the therapy declined the invitation, largely because of the “high treatment intensity” burden.