Patients who underwent radiation therapy to treat breast cancer may have an increased risk of developing certain types of skin cancers, according to recent research published in JAMA Network Open. Although instances of these secondary diseases are rare, patients need to be aware of them, explained study author, Shawheen J. Rezaei.
“Breast cancer is a leading cause of cancer in the U.S., and radiation plays an important role in the treatment of breast cancer for many patients,” Rezaei, who is an MD Candidate and Knight-Hennessy Scholar at Stanford University School of Medicine in Palo Alto, California, said in an interview with CURE®. “We wanted to study the incidence of skin cancer after breast cancer radiation to help patients and physicians be aware of considerations for follow-up care after their cancer treatment.”
Rezaei and his team analyzed data from 875,880 patients who were newly diagnosed with skin cancer — 50.3% of whom underwent radiation therapy. Among the entire group, a total of 3,839 patients developed nonkeratinocyte skin cancer, which included melanoma (89.1% of cases), Merkel cell carcinoma (3.2%), hemangiosarcoma (2.7%) and other types of nonkeratinocyte skin cancers (5.1%).
Study findings showed that the risk of these types of skin cancers on the breast or trunk after a breast cancer diagnosis was 57% higher in patients who underwent radiation. When it came to the instance of nonkeratinocyte skin cancer anywhere on the body, those with previous radiation exposure had a 26% higher risk.
This is not the first study to discover a link between radiation and skin cancer.
In fact, the American Academy of Dermatology (AAD) explained on its website, “Anyone who has had radiation treatments has a higher risk of developing skin cancer in that area. Skin cancer tends to show up many years later, so this makes sun protection essential for life.” The AAD urges patients to monitor their skin in the area that received radiation and to call their oncologist or dermatologist if they notice redness, rash or other changes.
However, Rezaei noted that since the occurrence of post-radiation nonkeratinocyte skin cancers is still rare, patients should not worry about altering their treatment plan, especially since, as noted in the study, “radiation therapy results in a notable reduction of both breast cancer recurrence and mortality.”
Instead, patients whose breast cancer is treated with radiation should consider doing skin checkups after undergoing treatment, Rezaei said.
“The findings of our study should not change a patient’s breast cancer treatment plan. Receiving breast cancer radiation may be a very important aspect of a patient’s breast cancer treatment, and all treatment decisions should be made in collaboration with an oncologist. Our findings may encourage patients to receive skin exams following their breast cancer treatment,” he said.
Rezaei also mentioned that one limitation of the study was that it did not investigate if there were any patient characteristics — such as certain genetic markers — that may increase a patient’s risk of developing nonkeratinocyte skin cancer after breast cancer radiation, though he mentioned that, “We hope future studies could help shed light on different risk levels for different patient groups.”
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