Tanning: Cancer Cause on 'Covered' Skin?
Biggest Jump in Common Skin Cancer on Areas Not Exposed to Everyday Sun
Intentional Tanning May -- or May Not Be -- to Blame continued...
He notes that about half of his countrymen travel to sunny climes during vacation, and one in three women and one in five men visit tanning salons. Nearly half of 10,000 Swedes surveyed report having had a sunburn in the past year.
His study, published in the July issue of Archives of Dermatology, tracked more than 50,000 cases of squamous cell carcinomas -- but not other skin cancers -- that occurred between 1961 and 1988.
What it didn't do, says one expert not involved in the study, was examine other potential risk factors that could explain Sweden's boost in all squamous cell carcinomas.
"There's no disputing that UV rays can cause squamous cell carcinomas; they're not the only cause," says Ella L. Toombs, MD, a Washington dermatologist and former FDA medical officer.
"One of the potential causes of squamous cell carcinomas is there's a defect in the gene that repairs DNA and prevents development of skin cancer. But we don't know from this study the genetics of these individuals, or how their genetics evolved over this 30-year period. We don't know if these people have arsenic in their drinking water. We don't know if these families had another disorder that can explain their rates of skin cancer. We don't know what environmental changes occurred in Sweden since 1961 that may play a role.
"These authors don't include or exclude other potential factors; they just jump to the conclusion that tanning is the cause," she tells WebMD. "In the U.S., African Americans have an equal incidence of squamous cell carcinoma on exposed and non-exposed skin areas. Are we going to say they're going to tanning beds? I don't think so."