Do ED Drugs Raise the Risk of Malignant Melanoma?

The use of phosphodiesterase type 5 (PDE5) inhibitors for the treatment of erectile dysfunction (ED) is unlikely to increase the risk of malignant melanoma, according to the results of a recent study.

Previous research has suggested that inhibition of PDE5 expression could increase the invasiveness of melanoma cells, and, therefore, that PDE5 inhibitors could increase the risk of developing melanoma. The aim of the current study was to further investigate the association between PDE5 inhibitor use and melanoma risk, and determine whether the relationship could be causal.
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The researchers conducted a matched cohort study using data from the UK Clinical Practice Research Datalink, including 145,104 men initiating a PDE5 inhibitor and with no prior cancer diagnosis matched with 560,933 healthy controls.

Overall, 1315 incident malignant melanoma diagnoses were recorded during follow-up (mean follow-up 4.9 years). After adjusting for confounders, the researchers observed a small positive association between PDE5 inhibitors and the risk of malignant melanoma.

However, similar increases were observed in the risk of basal cell carcinoma and solar keratosis, both known to be related to sun exposure, but no increase in the risk of colorectal carcinoma was observed. No link was observed between the number of prescriptions and an increase in risk.

“Our results were not consistent with PDE5 inhibitors being causally associated with melanoma risk, and strongly suggest that observed risk increases are driven by greater sun exposure among patients exposed to a PDE5 inhibitor,” the authors wrote.

—Michael Potts

Reference:
Matthews A, Langan SM, Douglas IJ, Smeeth L, Bhaskaran K. Phosphodiesterase type 5 inhibitors and risk of malignant melanoma: matched cohort study using primary care data from the UK Clinical Practice Research Datalink [published online June 14, 2016]. PLoS Med. doi:10.1371/journal.pmed.1002037.