Katherine Hobson Blog on WSJ May 25 2010
http://blogs.wsj.com/health/2010/05/27/study-suggests-indoor-tanning-boosts-chances-of-melanoma/
Last year the International Agency for Research on Cancer added indoor tanning to its list of carcinogens, but the evidence it relied on showed only a weak link between using sunbeds and the risk of melanoma, a rare but deadly form of skin cancer.
Research out today, though, suggests a much stronger tie — specifically, that people who tanned indoors had a 74% higher chance of developing melanoma than those who hadn’t. (Because melanoma is rare, that’s still a pretty low risk.)
The study, which appears in the journal Cancer Epidemiology, Biomarkers & Prevention, took a group of 1,167 people diagnosed with melanoma and compared their tanning habits to a similar, randomly selected group of 1,101 people. That type of study has the potential for biases, but the researchers said they attempted to correct for that as much as possible.
Researchers concluded that contrary to the IARC’s findings, the age at which someone starts tanning indoors isn’t the important factor in melanoma risk; instead, they say cumulative exposure is the key. Previous research has suggested that the risk of melanoma increases with sunburns and intermittent exposure to the sun, such as the kind you get on vacation or in sunbathing sessions, and these findings agree, study author DeAnn Lazovich, a cancer epidemiologist at the University of Minnesota, tells the Health Blog. When it comes to melanoma risk, “it doesn’t matter if you’re exposed from artificial or solar sources” of UV rays, she says.
Interestingly, this and other studies haven’t found links between melanoma and total sun exposure or the kind of chronic exposure you get from working or regularly doing a sport outdoors. The tanning industry cited that, among other issues — including the fact that fair-skinned Minnesotans are more likely to develop melanoma so don’t accurately represent the U.S. population — in its criticisms of the research.A review of human carcinogens--part D: radiation.