US Pharm. 2018;43(6):3.

As we report in this issue’s Clinical News Digest, some startling news emerged last month concerning an apparent link between daily aspirin use in men and a greater risk for melanoma. In fact, the peril in this population, according researchers at the Northwestern University Feinberg School of Medicine, is nearly twice that compared to men who do not take aspirin each day.

The potential impact is enormous. Almost half of people aged 65 years and older reported taking aspirin daily or every other day, according to a 2005 study. In 2015, about half of a nationwide survey of U.S. adults reported regular aspirin use, according to study published in April 2018 in the Journal of the American Academy of Dermatology.

Moreover, in an article in this issue’s Health Systems edition titled, “Updates in Pharmacotherapy for Melanoma,” the authors report that in 2016, an estimated 76,380 people in the United States would be diagnosed with melanoma and about 10,130 would die of this disease.

The unsettling finding will no doubt spur additional work into possible causes. Senior study author Beatrice Nardone, MD, PhD, research assistant professor of dermatology, Northwestern University, theorizes that men may be more susceptible to developing melanoma because they express a smaller amount of protective enzymes, such as superoxide dismutase and catalase, compared to women.

“These lower levels of protective enzymes suggest that a higher level of resulting oxidative cellular damage in men might contribute to the possibility of developing melanoma,” said Dr. Nardone, an investigator for the Research on Adverse Drug Events and Reports program at Northwestern. She recommends ramping up patient education about sun exposure, avoiding tanning beds, and having regular skin checks by a dermatologist, particularly for people at high risk for skin cancers. Somewhat downplaying the findings that imply an association between aspirin use and the skin cancer, however, Dr. Nardone said, “This does not mean men should stop aspirin therapy to lower the risk of heart attack.”

The Northwestern study collected medical record data comprising almost 200,000 patients who were aspirin-exposed or aspirin-unexposed (control group), aged 18 to 89 years, with no prior history of melanoma and with a follow-up time of at least 5 years. The aspirin-exposed patient population included only patients who had at least 1 year of once-daily aspirin exposure at a dose of 81 mg or 325 mg between January 2005 and December 2006.

Out of a total of 195,140 patients, 1,187 were exposed to aspirin. Of these 1,187 patients, 26 (2.19%; both men and women) had a subsequent diagnosis for melanoma compared to 1,676 (0.86%) in aspirin-unexposed (men and women) patients. When the gender groups were separated, men exposed to aspirin had almost twice the risk for diagnosis of melanoma (adjusted relative risk, 1.83) compared to men in the same population who were not exposed to aspirin.

Fortunately, as the authors of this issue’s Health Systems edition article report, survival rates have started to improve because of new and emerging systemic therapies, including immunotherapy and targeted therapy for specific genetic alterations in distinct clinical subtypes of melanoma, and local therapies. Clinical studies have established recommended treatment options including checkpoint immunotherapy, BRAF-targeted therapy for patients with BRAF-mutated disease, and clinical trials as first-line therapy for unresectable or metastatic disease.

Nevertheless, this disquieting development demands further examination, especially for the peace of mind of men interested in prophylactic cardiovascular disease prevention but who worry about skin cancer, especially melanoma.

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