Men who take daily aspirin for more than a year have a significantly increased risk of developing malignant melanoma, according to study findings published in the Journal of the American Academy of Dermatology (online, 27 March 2018)
The researchers used data from Chicago, Illinois, concerning people who took daily aspirin (81mg or 325mg) for at least one year continuously. The patients were followed up for a minimum of five years and compared with those who did not take daily aspirin. In total, the study used data from over 193,000 patients.
The team found that overall, the relative risk of a malignant melanoma diagnosis after at least one year of chronic exposure to aspirin was 1.46, compared with unexposed individuals. However, when they stratified the results according to gender, aspirin was associated with a 1.83 relative risk of malignant melanoma in men and there was no significant association in women.
The researchers said there was no clear mechanism of action to explain the findings. However, lead author Beatrice Nardone, assistant professor of dermatology at Northwestern University Feinberg School of Medicine in Chicago suggested they could be related to hormonal difference between males and females that confer lower protection against oxidative cellular damage in males.
“Given the widespread use of aspirin and the potential clinical impact of the link to melanoma, patients and healthcare providers need to be aware of the possibility of increased risk for men,” she said.
However, the researchers said the results did not mean that males taking aspirin for cardioprotection should stop taking it.
 Orrell KA, Cices AD, Guido N et al. Malignant melanoma associated with chronic once daily aspirin exposure in males: a large, single-center, urban, US patient population cohort study from the Research on Adverse Drug events And Reports (RADAR) project. Journal of the American Academy of Dermatology 2018. doi: 10.1016/j.jaad.2018.03.031