June 23, 2015

expert reaction to erectile dysfunction medicine and melanoma

A study has been published in the journal JAMA which investigates a potential link between medicine used to treat erectile dysfunction and skin cancer.

Prof. Stephen Evans, Professor of Pharmacoepidemiology, London School of Hygiene and Tropical Medicine (LSHTM), said:

“The authors of this study are appropriately cautious in the interpretation of their data. The estimate of increased risk is small, and reduced by adjusting for the available confounding factors. This adjustment will be incomplete inevitably because of imprecision in recording those factors. In addition a key factor is exposure to sun, and the data on this (and other possible relevant factors) were not available. The risk of malignant melanoma associated with increased income was notably larger than that associated with ED drugs. This may also be associated with exposure to sunlight. It may be the wealthy who are able to travel to the sun in Sweden’s winter! It may be that those who travel are also more likely to use ED drugs.

“This study is extremely weak evidence for an increase in risk of malignant melanoma with ED drugs, and seems much more likely to be associated with other factors, especially exposure to sunlight.”

Prof. Chris Chapple, Secretary General of the European Association of Urology, Consultant Urological Surgeon and Honorary Professor at Sheffield Hallam University, said:

“This paper reports a previously unreported potential association between the use of this type of drug – a PDE5 inhibitor for erectile dysfunction- and low stage melanoma. Whilst this is an interesting observation there is a lack of an association between dosing and incidence; the association was more noticeable in patients who had filled single prescriptions as compared to more prolonged exposure to this type of drug.

“It’s an interesting observation, but it should not be a trigger for any change in current clinical practice relating to the use of drugs for the treatment of erectile dysfunction such as Viagra and related compounds.”

‘Use of Phosphodiesterase Type 5 Inhibitors for Erectile Dysfunction and Risk of Malignant Melanoma’ by Loeb et al.  published in JAMA on Tuesday 23^rd June.

Declared interests

Prof. Stephen Evans: I have no conflicts of interest to declare
Prof. Chris Chapple: None received