Researchers at the Montefiore Einstein Cancer Center (MECC) in New York have found that many cases of acute radiation dermatitis (ARD) due to cancer treatment involve a common skin bacterium. Their findings suggest that a simple, low-cost treatment can prevent severe cases, potentially setting a new standard of care for people of all skin types undergoing radiation therapy.
“Until now, ARD was assumed to result simply from the skin being burned by the radiation, which meant that not much could be done to prevent it,” said the senior author of both papers, Dr. Beth N. McLellan, in a press release. “The readily available treatment we’ve developed and clinically tested could potentially save hundreds of thousands of people each year in the U.S. from severe ARD and its excruciating side effects.”
Dr. McLellan is the Director of supportive oncodermatology at MECC and Chief of the Division of Dermatology at Montefiore Health System and Albert Einstein College of Medicine.
The researchers suspected that S. aureus, known to be involved in skin disorders that lead to a breakdown in the skin, might play a role in ARD.
In one of the JAMA Oncology studies, the MECC researchers enrolled 76 patients undergoing radiation therapy for cancer. Bacterial cultures were collected from patients before and after radiation treatment, from three different body sites: inside the nose, from skin in the radiated area, and from skin on the side of the body not exposed to radiation.
Before treatment, approximately 20% of patients tested positive for SA but did not have an active infection. Following treatment, 48% of those patients who developed severe ARD tested positive for the presence of SA, compared with only 17% of patients who developed the mildest form of the condition. Many patients with SA on their skin also tested positive for nasal SA, suggesting that SA from the nose might be infecting the skin.
“This study clearly showed that SA plays a major role in ARD,” said Dr. McLellan. “The good news is we have a lot of tools to fight this bacteria. In a second study, we tested a topical antibacterial drug combination we thought would be effective and easy for people to use.”
The second study enrolled 77 patients undergoing radiation therapy, all but two of whom had breast cancer. Participants were randomized to receive either the standard of care at MECC—a combination of normal hygiene and moisturizing treatment—or the experimental antibacterial regimen. This treatment involved using the body cleanser chlorhexidine along with mupirocin 2% nasal ointment twice a day for five days, every other week, throughout their radiation treatment.
Although more than half the patients treated with the antibacterial regimen developed mild-to-moderate ARD, no patients developed moist desquamation—the most severe type of ARD that causes the skin to break down and develop sores—and no patients experienced adverse effects from the treatment. In contrast, severe ARD affected 23% of participants receiving the standard of care.
“Our regimen is simple, inexpensive, and easy so we believe it should be used for everyone undergoing radiation therapy, with no need to first test individuals for SA,” said Dr. McLellan. “I expect this will completely change protocols for people undergoing radiation therapy for breast cancer.”
Dr. McLellan also noted: “Like most of our trials at MECC, a majority of our participants were Black and Hispanic members of our community, meaning this protocol is generalizable and effective for people of different races and ethnicities. This is especially important because people with darker skin types are more likely to develop severe ARD.”