The incidence of melanoma, the most deadly form of skin cancer, has increased dramatically among middle-aged adults in the last four decades, according to a new study out from the Mayo Clinic.
The study, published in the January issue of Mayo Clinic Proceedings, looked at the overall incidence of skin cancer between 1970 and 2009 among the fastest-growing segment of the U.S., men and women 40 to 60 years old. Skin cancer rates for men increased 4.5 fold while skin cancer rates for women increased an astonishing 24-fold.
Researchers point to tanning beds and their accompanying UV radiation as a likely culprit, particularly with regard to the high rate of skin cancer in this younger group of women.
“Although this study didn’t look at risk factors particularly associated to this rise in incidence, we tend to think that habits and behaviors that were common back in the 1970s and 1980s are perhaps catching up with society now,” said dermatologist Dr. Jerry Brewer, principal investigator of the study.
“If you look at some of the statistics with tanning beds, for example, one session in a tanning bed increases your chance of melanoma by 20 percent. Nowadays it’s been found that in women between the ages of 18 and 29, 76 percent of their melanomas are associated with tanning bed use. Things like that make us think that the behaviors that were common back in the ‘80s are catching up with middle age women now.”
Dr. Margaret Madeleine, epidemiologist in the Public Health Sciences Division at Fred Hutchinson Cancer Research Center, said behavior is definitely a factor with regard to the bump in skin cancer rates.
“The increase, specifically in women and in this age group, really suggests that more needs to be done to get the information out about tanning and the damage it can do to susceptible people,” she said.
A study just out in JAMA Dermatology sheds light on just how prevalent tanning bed use has become, particularly among teens and young adults. The study, a systematic review and meta-analysis of more than 490,000 participants and 88 studies from 16 countries, found that 14 percent of adults, 43 percent of university students and 18 percent of adolescents had used an indoor tanning bed within the last year.
Why do people continue to tan even though the International Agency for Research on Cancer, part of the World Health Organization, has categorized tanning devices that emit UV radiation as carcinogenic to humans?
A survey of sorority sisters released Wednesday by the North Carolina Lineberger Comprehensive Cancer Center provides some answers. According to the survey, 30 percent of the women questioned had used tanning beds in the last year and the majority of users had tanned since their teens. Tanners pointed to “improvement in appearance” as the main reason why they tanned. Others factors cited by those surveyed were “convenience” and “mood enhancement.” Tanning, the women said, reduced stress and helped them relax.
“Tanning beds are a real danger,” said Madeleine, who added there have been studies looking into the addictive nature of the practice. “This is an emerging threat that we’re only starting to get our hands around. For me, it seems like an opportunity to get a handle on a preventable exposure. If there’s any way to interrupt people getting melanoma, it’s a really important public health charge.”
In October of last year, Australia banned the use of tanning beds, citing a study estimating that 1 in 6 melanomas in young Australians 18 to 29 years old could be prevented if tanning salons were shut down. Here in the U.S., California, Illinois, Nevada, Texas and Vermont ban the use of tanning beds for minors under the age of 18.
“It’s hard for adolescents to understand the long-term impact of their habits,” said Madeleine. “They just want to look good in the moment. But it’s an important message to get across. I think behavioral research needs to be done to try to get the message out. And we also need the epidemiologic research to understand the parameters of the exposure.”
According to the American Cancer Society, more than 3.5 million cases of basal and squamous cell skin cancer are diagnosed each year in the U.S. In 2013, there were more than 76,600 cases of melanoma. Studies show that indoor tanning before the age of 35 increases the risk of melanoma by 59 to 79 percent and tanning before the age of 25 increases non-melanoma skin cancer risk from 40 to 100 percent.
Madeleine said indoor tanning increases risk of all types of skin cancer, and suggests that we need to focus our attention on teaching sun avoidance at an early age.
Reach writer Diane Mapes at dmapes@fredhutch.org.
