Risk and protective factors
New data have implicated medications used to treat erectile dysfunction (ED) as a risk factor for melanoma, raising concern given their widespread use, Dr. Venna said.
A cohort study found that melanoma risk was 84% higher with recent use of sildenafil (Viagra) and 92% higher with ever use (JAMA Intern Med. 2014;174:964-70). But the absolute number of excess cases was fairly small.
A case-control study looking at all types of ED drugs found that receipt of a single prescription was associated with a 32% higher risk of melanoma (JAMA. 2015;313:2449-55). Use increased risk of in situ and stage I melanoma, but not more advanced disease. There was no difference between short- and long-acting agents.
“Prospective studies with clearly defined inclusions and exclusions are needed, with dosing in particular,” Dr. Venna summed up. “There appears to be a modest association, but it certainly is not enough to call for widespread discontinuation. In the patients who are on these drugs, it’s good to document [use] until we have more clarity about the biologic effects of this ultimately.”
A study using dietary surveys and having an average follow-up of more than a decade showed that coffee drinkers had a 20% lower risk of melanoma relative to nondrinkers (J Natl Cancer Inst. 2015 Jan 20;107(2)). But benefit was significant only among the subset drinking at least 4 cups a day.
“It’s premature to advise coffee intake based on this paper, although it does build upon an earlier Norwegian study from the 1990s which showed a similar trend,” Dr. Venna said. “At the end of the day, these data are intriguing, but obviously there are a lot of side effects of trying to consume 4 cups of coffee a day, so further study is certainly warranted.”
Dr. Venna disclosed that he had no relevant conflicts of interest.