PDE5 Inhibitors and Melanoma Risk: Is There an Association?
Phosphodiesterase type 5 (PDE5) inhibitors are widely used to treat erectile dysfunction. They act by inhibiting cyclic guanosine-39,59-monophosphate (cGMP)-degrading PDE5 in vascular smooth muscle. Activation of this same pathway has also been shown to promote melanoma cell growth. Therefore, some studies have tried to determine whether there might be an increased risk of melanoma after use of a PDE5 inhibitor. Thus far, the results have been inconclusive.
A recent meta-analysis looked at all the available evidence to date to determine the possible association between use of PDE5 inhibitors and risk for development of skin cancers. In addition, the authors assessed the strength of the results from the available studies.
The authors were able to cull 3 cohort studies and 2 case-control studies from 294 citations they retrieved from electronic databases. The studies involved a cumulative total of 998,456 participants. The results of the meta-analysis show that PDE5 inhibitor use is slightly but significantly associated with increased risk for development of melanoma and basal cell carcinoma.
There were some confounding variables within this association. For example, the greater sun exposure that was seen among users of PDE5 inhibitors may also increase the melanoma risk. Also, the melanomas that were found among PDE5 inhibitor users were at earlier stages than among nonusers. This finding suggests that the slightly elevated risk for development of melanoma might be attributable to more health-seeking behaviors in this population.
The authors conclude that while the increase in risk is significant, causality remains elusive and there are many potential confounders. They note that future well-conducted prospective studies are warranted to further explore the modest association.
Byline: Martha L. Sikes, MS, RPh, PA-C
Posted: December 11, 2017
Adapted from the original article.