Hyperbaric therapy no benefit in radiation-related chronic GI symptoms

Last Updated: 2015-12-28

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - Hyperbaric oxygen therapy does not benefit patients with radiation-induced chronic gastrointestinal (GI) symptoms in the long term, according to new research from the UK.

"We found no evidence that patients with radiation-induced chronic gastrointestinal symptoms, including those patients with rectal bleeding, benefit from hyperbaric oxygen therapy. These findings contrast with evidence used to justify current practices, and more level 1 evidence is urgently needed," the study authors wrote in an article online December 15 in the Lancet Oncology.

"These findings surprised us, given the general assumption that hyperbaric oxygen often benefits patients suffering chronic side effects of radiotherapy after cure of a pelvic cancer," principal investigator Dr. John Yarnold, of the Institute of Cancer Research and the Royal Marsden National Health Service (NHS) Foundation Trust in London, UK, told Reuters Health by email.

Dr. Yarnold and colleagues conducted the double-blind phase 3 HOT2 study of patients age 18 and older in 10 treatment centers. Study participants had chronic GI symptoms for 12 months or longer after radiotherapy that persisted after at least three months of optimal medical therapy and no evidence of cancer recurrence.

Between August 2009 and October 2012, 55 participants received hyperbaric oxygen and 29 were given sham therapy.

Participants in the treatment group breathed 100% oxygen at 2.4 atmospheres of absolute pressure (ATA) and those in the control group breathed 21% oxygen at 1.3 ATA. Both groups received 90-minute air pressure exposures once a day for five days a week for eight weeks for a total of 40 exposures.

The primary endpoints were bowel-related changes in the modified Inflammatory Bowel Disease Questionnaire (IBDQ) score and the IBDQ rectal bleeding score 12 months after the start of treatment. Patients who did not provide IBDQ scores within a predetermined time period were excluded. All participants completed 12 months of follow-up.

Of 46 participants in the treatment group and 23 participants in the control group, the authors found no significant differences in the change of IBDQ bowel component score (median change of 4 in each group).

Analyzing 29 participants in the active treatment group and 11 participants in the sham group with rectal bleeding at baseline, they found no significant differences in the change of IBDQ rectal bleeding score (median change of 3 and 1, respectively).

Adverse events in both groups included eye refractive changes, increased fatigue, and ear pain. Eight serious adverse events in the sham group included tonsillitis requiring surgery and vulvar cancer. Six serious adverse events in the treatment group included malignant spinal cord compression requiring surgery, malignant para-aortic lymph node involvement requiring surgery, and aneurysm.

The results contradict the earlier randomized controlled HORTIS trial, which showed clinical benefit of hyperbaric oxygen therapy in patients with GI symptoms after radiotherapy for cancers of the endometrium, uterine cervix, uterine corpus, prostate, colon, or rectum, the authors wrote.

"Ours is only one of two randomized trials testing hyperbaric oxygen in patients with bowel problems after pelvic radiotherapy, despite the treatment being used for decades," Dr. Yarnold said.

Dr. Carien L. Creutzberg, professor of radiation oncology at Leiden University Medical Center in the Netherlands, and author of an accompanying comment, agreed with the authors regarding a need for further randomized controlled trials.

"Hyperbaric oxygen therapy is widely used as a treatment for a wide range of chronic radiation-induced tissue injuries, despite lack of firm evidence of efficacy and cost-effectiveness," she told Reuters Health by email.

"It is to be hoped that more studies of alternative treatments for chronic radiation-induced gastrointestinal dysfunction will be stimulated, and that randomized controlled studies of hyperbaric oxygen therapy for other indications will be done, as it is used for a wide range of radiation-related problems (fibrosis, pain, ulcers)," added Dr. Creutzberg.

Cancer Research UK and the NHS funded this research. The authors reported no disclosures.

SOURCE: http://bit.ly/1YNx89G and http://bit.ly/1Uec9eP

Lancet Oncol 2015.