Outdoor Exercise, Viagra Use
and Melanoma Risk

Readers who exercise regularly in the sun in addition to taking medication for ED should be sure to slather on the sunblock this summer. New observational research suggests an association between sildenafil (Viagra) use and melanoma. The evidence is in its earliest stages, and causality remains unclear. Still, the retrospective study potentially delivers yet another reason that routinely protecting the skin from the sun’s harmful UV rays is always a good idea.

Published recently in JAMA Internal Medicine, the study analyzed data from almost 26,000 U.S. men. In 2000, participants in the Health Professionals’ Follow-up Study were questioned regarding sildenafil use for erectile dysfunction. Participants who reported cancers at baseline were excluded. The incidence of skin cancers including melanoma, squamous cell carcinoma and basal cell carcinoma was obtained in self-reported questionnaires every two years. Melanoma and squamous cell carcinoma diagnoses were pathologically confirmed.

Men who had recently used sildenafil had nearly twice the risk for developing melanoma after adjustment for other risk factors. Men who had used sildenafil at any time faced a similar increase in risk. A secondary analysis excluding those reporting major chronic diseases at baseline “did not appreciably change the findings,” and there was no significant association between erectile function by itself and melanoma. The authors understand the findings are as of yet insufficient to alter current clinical recommendations. Prospective studies are required before clinical recommendations should undergo any changes.

Early detection of melanoma is considered critical. As Harvard Health Publications points out, although it accounts for less than five percent of all skin cancer cases, melanoma is responsible for the vast majority of skin cancer deaths. This form of cancer starts in cells deep in the epidermis called melanocytes, or in moles on the surface of the skin that produce pigment. Early treatment is important to help prevent this cancer from spreading throughout the body.

Harvard notes that rates of melanoma have been rising for at least the past 30 years. Your risk of developing melanoma is higher if you have red or blond hair; green or blue eyes; fair skin; a history of being in the sun a lot, especially as a child; and an immediate relative (such as your mother or father or a sister or brother) with melanoma.

Of particular concern are new moles appearing after age 30; a new mole at any age if it is in an area rarely exposed to the sun; a change in an existing mole; and one or more “atypical moles”: these include moles that are darker than others or have an irregular border or shape.

Melanoma has several distinguishing characteristics that experts call the ABCDEs. A mole or growth is considered suspicious if:

it is Asymmetrical;
its Borders are irregular or blurry;
its Color is unusual;
its Diameter exceeds 6 millimeters (about the width of a pencil eraser);
it has Evolved (enlarged or changed) in any way.

If you have a mole or moles with any of these characteristics, see your doctor for a thorough skin exam.

JAMA Intern. Med., published online April 7, 2014, DOI:10.1001/jamainternmed.2014.594, http://archinte.jamanetwork.com/article.aspx?articleID=1857095

Harvard Healthbeat, April 2014, “Melanoma — Early Detection and Treatment are Critical”

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