For the first time ever, a study has found a definitive link between indoor tanning and melanoma. The study by University of Minnesota researchers found a strong association between tanning-device use and the most serious form of skin cancer.
Researchers found that people who use any type of tanning device, for any amount of time, are 74 percent more likely to develop a melanoma.
The University of Minnesota study is published in the online edition of "Cancer Epidemiology, Biomarkers and Prevention," a journal of the American Association for Cancer Research.
Epidemiologist DeAnn Lazovich hopes her findings will convince the public -- especially young people -- to give up indoor tanning. She also thinks the findings make a strong case for tightening restrictions on tanning devices.
“My practice has become an overwhelming one of seeing, diagnosing and treating skin cancers.”Dr. Cindy Firkins Smith, dermatologist
"Ultraviolet radiation, whether it comes from the sun or it comes from artificial devices like indoor tanning, is not safe," said Lazovich, a Ph.D. researcher and associate professor of epidemiology.
Previous studies have come to similar conclusions. But for the most part, those studies found a much weaker association between indoor tanning devices and melanoma. Lazovich said the earlier studies had some pretty significant limitations which she tried to resolve.
Her study is the largest of its kind. University researchers surveyed more than 1,100 Minnesotans diagnosed with melanoma and compared them with 1,100 people of similar ages, without melanoma. The melanoma-free group was randomly selected from state driver's license lists, and matched by gender against the list of people with melanoma.
The study involved only recently diagnosed melanoma patients. It also took into account other factors that can confuse study results, such as sun exposure and differences between regular tanning beds and enhanced UV devices that emit more radiation.
After controlling for all of those factors, Lazovich found an increased risk of melanoma among indoor tanners, no matter which way she measured their exposure.
"We have found an especially strong relationship with tumors on the trunk -- and we found that both in men and in women," she said. "And women, of course, would not normally bare their trunks unless they were deliberately getting a tan of some sort or exposing themselves to the sun."
People who tan indoors frequently had the highest risk of developing melanoma. Frequent use was defined as more than 100 sessions, 50-plus hours of tanning or for more than 10 years. Those tanners were two-and-a-half to three times more likely to develop melanoma than people who did not tan indoors.
Dr. Jennifer MacGregor, a clinical professor of dermatology at Georgetown University Medical Center, considers the U of M study strong research. She did not participate in the work, but evaluated it.
"This is exciting for us because I think that this study finally confirms in a nice way, with a large number of patients, what dermatologists have known for years," MacGregor said.
The findings also come as no surprise to Dr. Cindy Firkins Smith. The Willmar, Minn. dermatologist has been in practice for 20 years. When she first started, Smith saw a new melanoma case maybe every two or three months. But now it's much more common.
"There is not a week that goes by that I don't see a new melanoma," Firkins Smith said. "Occasionally I see two or three new melanoma referrals per week. My partner and I had five or six in one day once. My practice has become an overwhelming one of seeing, diagnosing and treating skin cancers."
Smith has a half-dozen female patients who were diagnosed with melanoma before the age of 25. All of them used indoor tanning devices, even though they were aware of the cancer-related risks.
"DeAnn's study is wonderful," she said. "But I've been telling people that for years and I don't know that I'm making any headway. It's very frustrating."
Smith said some research in teens suggests that if they're told about their risk of premature aging, rather than their risk of getting skin cancer, they might be less inclined to use artificial tanning devices. But she thinks ultimately, tougher regulations hold the most promise.
State legislatures have the power to restrict the devices. In Minnesota, children under age 16 are required to have a parent's "in-person" consent to use artificial tanning.
The federal Food and Drug Administration is reviewing recommendations from a scientific advisory committee to ban indoor tanning use in adolescents. Smith and others say if the FDA doesn't act on the recommendations, they will try to convince state lawmakers to ban children under age 18 from using the devices.