Each year, according to Montefiore Einstein Cancer Center (MECC) researchers, 10 million people in the United States are treated with radiation therapy to reduce the size of their tumors. They said acute radiation dermatitis (ARD), characterized by red, sore, itchy, or peeling skin, affects up to 95 percent of people undergoing radiation treatment for cancer.

 

The researchers said that severe cases of ARD can cause significant swelling and painful skin ulcers that can severely impair quality of life. Yet, up to recently, they said little was known about why the condition occurs, and no standardized treatments for preventing severe ARD have been widely adapted.

 

The good news is that recently, researchers at MECC have found that many cases of ARD involve a common skin bacterium, and that a simple, low-cost treatment can prevent severe cases, potentially setting a new standard of care for people undergoing radiation therapy. Their findings were reported in two papers published on Friday, May 5, in JAMA (Journal of the American Medical Association) Oncology.

 

Beth N. McLellan, M.D. is director of supportive oncodermatology at Montefiore Einstein Cancer Center (MECC), chief of the division of dermatology at Montefiore Health System and Albert Einstein College of Medicine, and senior author of the two studies. “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,” McLellan said. “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.”

 

Identifying the Source

Staphylococcus aureus (SA) bacteria, often shortened to “staph,” typically live harmlessly on the skin, often in the nose and armpits, according to the MECC team. However, they can cause infections if the skin is broken by a cut, the researchers said. “Radiation weakens the skin’s structure at the treatment site and can result in infection by allowing SA to break through the skin’s outer layer,” MECC researchers said. “Courses of radiation therapy, routinely requiring daily treatments over several weeks, increase the risk for skin infection to occur.”

 

McLellan and her colleagues reasoned that the bacteria might also play a role in ARD, since SA is implicated in common skin disorders that lead to a breakdown in the skin, such as eczema. 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.

 

The researchers found that before treatment, approximately 20 percent of patients tested positive for SA, but did not have an active infection. Following treatment, they found that 48 percent of those patients who developed severe ARD tested positive for the presence of SA, compared with only 17 percent 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,” the researchers said.

 

“This study clearly showed that SA plays a major role in ARD,” said 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.”

 

Preventing Severe ARD

The second study enrolled 77 patients undergoing radiation therapy, all but two of whom had breast cancer, MECC researchers said. Participants were randomized to receive either the standard of care at MECC (normal hygiene and moisturizing treatment such as Aquaphor), or the experimental antibacterial regimen. The researchers said this treatment involved using the body cleanser chlorhexidine along with mupirocin 2 percent nasal ointment twice a day for five days, every other week, throughout their radiation treatment.

 

The researchers found that 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. Additionally, the researchers found that no patients experienced adverse effects from the treatment. In contrast, they said severe ARD affected 23 percent 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 McLellan. “I expect this will completely change protocols for people undergoing radiation therapy for breast cancer.”

 

McLellan added, “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.”

 

The research papers are titled “Staphylococcus aureus colonization predicts severity of acute radiation dermatitis,” and “Bacterial decolonization for prevention of radiation dermatitis: a randomized clinical trial.”

 

Co-authors on both papers include Yana Kost, B.A., Alana Deutsch, M.D., Nitin Ohri, M.D., M.S., H. Dean Hosgood, Ph.D., Johanna P. Daily, M.D., M.S. and Kosaku Shinoda, Ph.D. Additionally, Alexandra K. Rzepecki, M.D., and Mathew R. Birnbaum contributed to the S. aureus paper. Karolina Mieczkowska, M.D., Roya Nazarian, Ahava Muskat, B.S., Juan Lin, Ph.D., and Rafi Kabaritti, M.D., also contributed to the bacterial decolonization paper.

 

According to MECC, the center is a national leader in cancer research and clinical care, located in the ethnically diverse and economically disadvantaged borough of The Bronx, N.Y. MECC officials said the center combines “the exceptional science of Albert Einstein College of Medicine with the multidisciplinary and team-based approach to cancer care of Montefiore Health System.”

 

Founded in 1971 and a National Cancer Institute (NCI)-designated Cancer Center since 1972, MECC officials say the center is redefining excellence in cancer research, clinical care, education and training, and community outreach and engagement. They say its mission is to reduce the burden of cancer for all, especially people from historically marginalized communities.