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Viagra and Melanoma: Are they related? | Causes, Not Just Cases®

by: Kimberly Barone Baden

Skin cancer has certainly been at the forefront of news reports the past month, given the acting U.S. Surgeon General Boris D. Lushniak’s most recent report stating that 63,000 new cases of melanoma are diagnosed in the U.S. each year and an estimated 9,000 die each year from the disease. While the usual precautions, such as wearing sunscreen, avoiding tanning beds and seeking shade if outside, have been highlighted and discussed in media reports, there hasn’t been much discussion about Viagra and melanoma. Should there be?

A study, titled Sildenafil Use and Increased Risk of Incident Melanoma in US Men, published earlier this year by the American Medical Association found that “Sildenafil (the active ingredient in Viagra) use may be associated with an increased risk of developing melanoma.” How much of a risk? An eighty-four percent risk, to be exact.

While the study does not show direct cause and effect between Viagra use and the development of melanoma, it does show how Viagra might have unintended consequences on melanoma’s activity on a cellular level. And with approximately eight million prescriptions of Viagra written in 2012 alone, those potential consequences could be significant.

Viagra and Melanoma

Viagra basically works by stopping, or inhibiting, the PDE5A enzyme and allowing a blood flow-increasing enzyme to build up. As more blood flows, the greater a degree of an erection can be achieved.

Where the potential link to melanoma comes in is with stopping PDE5A. Blood flow reduction isn’t this enzyme’s only role in the body—there’s also the possibility that it can promote melanoma cell invasion.

What prompted this theory was a 2011 study lead by Dr. Imanol Arozarena, which found that the loss, or downregulation, of PDE5A “stimulate(s) a dramatic increase in melanoma cell invasion.”

Since Viagra also downregulates PDE5A, the researchers in this recent study hypothesized that there might be a link between melanoma and Viagra use.

Potential basis for the 84 percent boost

Using information gathered from the Health Professionals Follow-up Study—a Harvard study that has been ongoing since 1986 and which collects health data regularly from more than 50,000 health professionals—researchers identified eligible participants, some of whom reported taking sildenafil recently and some of whom reported taking it at some point between 2000 and 2010.

What the researchers found was that, during this 10-year time frame, 4.3 men out of every 1,000 who didn’t use Viagra developed melanoma while 8.6 out of every 1,000 who did use Viagra also developed melanoma. After adjusting for statistics, that difference was an 84 percent increase, leading to the conclusion that sildenafil users were 84 percent more likely to develop melanoma.

While more research needs to be completed into the relationship between Viagra and melanoma, this correlation is piquing the interest of the medical research community and hopefully inspiring a lot more research.

In the meantime, men taking Viagra should continue taking precautions when outdoors by protecting their skin from excessive sun exposure and visiting their doctors regularly for routine skin cancer examinations.