After analyzing data from over 20,000 men, researchers from the United States, Sweden, and the United Kingdom have concluded that erectile dysfunction (ED) drugs most likely do not cause melanoma, a form of skin cancer.
Their report was published in the June 23/30 edition of the Journal of the American Medical Association (JAMA).
Past research suggested a possible link between sildenafil (Viagra) and skin cancer. The current study investigated this connection further and included two other similar ED medications – vardenafil (Levitra) and tadalafil (Cialis).
The scientists examined medical records of Swedish men obtained from medical registers and databases. They took note of how many ED drug prescriptions the men filled, rates of melanoma, and disease stages. They also considered basal cell carcinoma, a type of skin cancer that acts differently from melanoma.
They identified 4,065 men with melanoma. An additional 20,325 men did not have melanoma and served as the control group.
The researchers found that 11% of the men with melanoma had filled a prescription for sildenafil, vardenafil, or tadalafil. Eight percent of the control group had done so.
While these results pointed to a “modest but statistically significant” increase of risk for melanoma among men who filled ED drug prescriptions, the researchers could not conclude that the drugs cause melanoma. They noted the following:
• First, risk was higher in men who filled one prescription only. Men who filled two or more prescriptions were not at significantly higher risk.
• Second, the drugs were associated only with higher risk for melanoma stages 0 and I. There was no association with stages II through IV.
• Third, there was also a connection between ED drugs and increased risk for basal cell carcinoma.
The scientists noted that if there was a causal relationship between ED drugs and melanoma, the above three findings would be unlikely.
Higher rates of melanoma among ED drug users might be explained by lifestyle. In this study, the men taking the ED drugs tended to have more education and higher incomes.
In a press release, lead author Stacy Loeb, MD, a urologist at New York’s NYU Langone Medical Center, explained, “What our study results show is that groups of men who are more likely to get malignant melanoma include those with higher disposable incomes and education—men who likely can also afford more vacations in the sun—and who also have the means to buy erectile dysfunction medications, which are very expensive.”
Resources
American Cancer Society
“What is melanoma skin cancer?”
(Last revised: March 20, 2015)
http://www.cancer.org/cancer/skincancer-melanoma/detailedguide/melanoma-skin-cancer-what-is-melanoma
Journal of the American Medical Association
Loeb, Stacy, MD, MSc, et al.
“Use of Phosphodiesterase Type 5 Inhibitors for Erectile Dysfunction and Risk of Malignant Melanoma”
(Full-text. June 23/30, 2015)
http://jama.jamanetwork.com/article.aspx?articleid=2338254&resultClick=3
NYU Langone Medical Center
“Viagra Does Something Very Important—But It Is Unlikely to Cause Melanoma, Researchers Conclude”
(Press release. June 23, 2015)
http://nyulangone.org/press-releases/viagra-does-something-very-important-but-it-is-unlikely-to-cause-melanoma-researchers-conclude