Chicago—Men who take daily aspirin to prevent cardiovascular events should be cautioned to take extra care to avoid skin cancer, suggests a new study finding that they have nearly double the risk of melanoma.

Interestingly, the report in the Journal of the American Academy of Dermatology, reports that women don’t appear to have the same risks.

“Given the widespread use of aspirin and the potential clinical impact of the link to melanoma, patients and health care providers need to be aware of the possibility of increased risk for men,” said senior study author Beatrice Nardone, MD, PhD, research assistant professor of dermatology at Northwestern University Feinberg School of Medicine.

Nardone recommended that those patients be urged to be careful about sun exposure, avoid tanning beds and get regular skin checks by a dermatologist, especially if they are already at high risk for skin cancer.

“This does not mean men should stop aspirin therapy to lower the risk of heart attack,” she emphasized.

The large, single-center, urban, U.S. patient population cohort study was part of the Research on Adverse Drug Events And Reports (RADAR) project.

For the research, the study team collected medical record data for nearly 200,000 patients who were aspirin-exposed or aspirin-unexposed (control group). Participants were aged 18 to 89 years, with no prior history of melanoma and with a follow-up of at least 5 years.

Only patients who had at least 1 year of once-daily aspirin exposure at a dose of 81 or 325 mg occurring between January 2005 and December 2006 were included in the aspirin-exposed group. Of the 1,187 selected, 2.19% had a subsequent diagnosis for melanoma compared to 0.86% of the 1,676 patients in the aspirin-unexposed group.

Researchers further determined that 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, although the same was not true for women.

Nardone said she was surprised at the results because aspirin has been linked to reduced risks of other cancers, including gastric, colon, prostate, and breast. In addition, previous studies have reported a reduced risk in aspirin-exposed men and an increased risk in aspirin-exposed women for some cancers.

Study authors speculate that men might be more vulnerable because males express a lower amount of protective enzymes, such as superoxide dismutase and catalase, compared with females.

“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,” Nardone posited.