Researchers at NYU Langone’s Laura and Isaac Perlmutter Cancer Center have developed a paste that prevents fibrosis — a type of scarring caused by radiation therapy. A study investigating the paste was published in the Journal of the Federation of American Societies for Experimental Biology.

“We envision that this approach will be helpful to individuals who receive radiation therapy as part of their treatment for cancer,” Dr. Bruce Cronstein, senior investigator of the study and director of NYU Langone's Clinical and Translational Science Institute, told HCB News. “Scarring and fibrosis following irradiation is a common problem that causes difficulties with both appearance and occasionally function (fibrosis restricts motion if it is in the right place).”

Scarring happens because key cells lay down tough connective tissue to establish a framework for healing after an injury. Fibrosis is a similar process, but it creates connective tissue in the wrong context and interferes with the function of tissues.

Radiation dermatitis is a type of fibrosis that as many as 95 percent of patients who undergo initial radiation treatment experience. For some patients, the effects are severe enough for them to stop treatment.

For the study, the researchers mimicked radiation dermatitis by exposing mice’s skin to a single dose of 40 Grays, which is a similar amount of radiation that cancer patients receive over the course of five weeks. Some of the mice were normal and others were genetically engineered to not have a protein receptor called adenosine A2A.

On a daily basis, half of the mice were treated with a topical paste that contained a patented A2A receptor blocker and the other half received a placebo. The paste contains 2.5 milligrams of active ingredient per milliliter of 3 percent carboxymethyl cellulose, which is a gum “binder” used to make drugs and other products.

After a month, the normal mice that received the placebo had a two-fold increase in the amount of collagen, skin thickness and fibrosis. The mice treated with the paste had only 10 percent more skin-thickening collagen and the mice genetically engineered to not possess the A2A receptor had no skin reaction.

If the paste comes into clinical practice, clinicians treating early-stage cancers with radiation could eventually prescribe an A2A inhibitor paste to prevent fibrosis, according to Cronstein. Women who are treated with radiation for early breast cancer are one example of the types of patients it could benefit.

“The changes in the texture and appearance of the skin after radiation can be a problem and if the agent works as well in people as in mice we expect these women to have a significant benefit,” wrote Cronstein.

Going forward, Cronstein and his fellow researchers plan to investigate the mechanism underlying the A2A receptor’s role in fibrosis.

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