Can a Pill Prevent Radiation-Induced Cancer?

Can a pill taken before an ionizing radiation imaging procedure prevent DNA damage that might lead to cancer? That’s what researchers suggest in their study just published in the July 2012 issue of Radiology.

Researchers investigated DNA double strand breaks before and after X-raying human blood mixed with a combination of antioxidants and glutathione-elevating agents.

This study is unique, according to co-author James Ehrlich, MD, because it looks at something very direct and specific, quantifying the double strand DNA breaks, a precursor lesion to cancer. He said that this is the first time it’s been shown that a pill given prior to radiation could protect the DNA from significant damage.

Ehrlich is a clinical associate professor of endocrinology at the University of Colorado, Denver, and an advisor to Premier Micronutrient Corporation which produces the BioShield formulation used in the study. He also has a financial interest in the company.

For the study, researchers used an assay developed by Michael A. Kuefner, MD, from the University of Erlangen-Nürnberg in Germany, which uses an immunofluorescence method to identify surrogate measures of double strand breaks in blood lymphocytes. Researchers used blood from 25 healthy human subjects. For the in vitro portion, the drawn blood was mixed with the BioShield formulation and irradiated, while for the ex vivo portion, the subjects swallowed the BioShield pill before their blood was drawn and irradiated. Non-irradiated samples served as a control.

Researchers found that the largest reduction (58 percent) in double strand breaks measured one hour after irradiation was from subjects who ingested the compound an hour before the imaging.

Radiation is known to produce free radicals which can damage the DNA. The most common way to prevent radiation damage is by lowering the dose and exposure time, shielding, and staying far away from radioactive sources. This compound is a different way that researchers hope to protect people from radiation damage. The compound contains antioxidants and glutathione-elevating agents like vitamins C and E and beta-carotene, given in high concentration.

Previously, the compound was tested during a number of animal studies in cooperation with NASA, the Defense Department and other government groups. In those trials, the animals were subjected to lethal doses of radiation. The studies showed that the animals treated with this compound either lived longer or had less tissue damage than their control counterparts.

“The animal studies were very striking,” Ehrlich said. “The human studies were confirmatory.”

He acknowledged that it’s not possible to do a study like those done in animals, looking at cancer rates in humans. “It would take too long, 15 years, and you can’t control for the other carcinogenic influences. The best you can do, in my opinion, was to see whether an initial step in carcinogenesis, the breakage of DNA, would be different if you pretreated people.”

Radiology ran a companion Science to Practice article analyzing the study, written by James Brink, MD, professor and chairman of diagnostic radiology at Yale, and John Boice, JR, ScD, of the National Council on Radiation Protection and Measurements.

“The study was very exciting from a methodological standpoint,” said Brink. “I was impressed with the methods by which the authors were able to assess the formation of double strand breaks in response to low doses of ionizing radiation using the fluorescent tagging technique.”

Brink said that while it would be difficult to conduct additional studies proving that the compound benefits patients, he feels it’s necessary if the health care system is to adopt this treatment on a wide-scale basis.

“I’m respectful of the challenges, but without a clear-cut identifiable clinical benefit, we only have a laboratory benefit,” he said. He noted that while many lab studies on the biochemistry of antioxidants have been encouraging, some clinical studies have not shown antioxidants to be beneficial to subjects. “That’s why we’d want to be cautious about jumping the gun,” he said.

Ehrlich said that he and his colleagues would like to do additional studies and they would be needed before this technique is widely adopted. He’d like to test the formulation on 100 patients already scheduled for a CT scan, rather than just irradiating their blood. However he said that the compound is safe, with no known side effects, and that even skeptics could find a business reason to offer the pill to patients who are concerned about radiation effects.

“From a business point of view, even radiologists who are not that worried about radiology levels, can purchase this from a financial point of view so they won’t lose patients (to facilities who offer it),” he said. BioShield is commercially available now, and Ehrlich said he’ll be selling the product on his own website within a few weeks, with plans to promote the pill to radiology groups.

While Brink said he’s not an expert on antioxidants, “cost alone is one consideration” for not using the pills without further study. But he also stressed that any medication could be harmful. “In general, it’s uncommon for any medication not to have some effect in some fashion,” he said. “Even over-the-counter medications can be harmful to you, as can dietary supplements.”

Brink added that the health care system now is less tolerant of adopting new treatments that haven’t shown evidence of clinical benefit. “We’ve made health care decisions in the past without outcomes-based proof,” he said, “but that’s not the trend these days.”