Melanoma, the deadliest form of skin cancer, still makes up just 3 percent of all skin cancers, and results in about 8,000 deaths a year, according to the National Cancer Institute. But three factors have doctors alarmed: The rates of this cancer are rising; it has become the most common cancer for young people; and many of the cases result from the preventable, but addictive, behavior of indoor suntanning.
"In the last few decades, it's certainly been on the rise. And some people think that may be a result of behavior, and UV exposure," said Jennifer Stein, an assistant professor of dermatology at New York University's Langone Medical Center. "This is a very serious cancer, and this is a behavior that's preventable."
Tanning and cancer go hand-in-hand.Without tanning beds, soaking up the rays was limited to clear days in the summer. The invention of the tanning bed changed that, and throughout the 1990s, the rapid proliferation of tanning salons provided venues for millions of people to sunbathe regardless of weather, season, or time of day.
During that same period, melanoma rates have increased by 2 percent in the general population, Stein said. Amongst young women, who make up 71 percent of tanning salon customers, incidents of melanoma have increased by 2.2 percent, Stein said. Over that time, skin cancer also became the most common form of cancer for Americans ages 25-29, a group that traditionally shows very low cancer rates, Stein said.
While some dermatologists believe that other factors, such as increased UV exposure resulting from the hole in the ozone layer, contribute to the rise in melanoma rates over the last 18 years, the irrefutable link between indoor tanning and melanoma makes tanning beds the prime suspect, Tsoukas said.
In a recent study conducted by researchers at the University of Michigan, frequent tanning bed users proved three times more likely to develop melanoma than non-users, and subjects that used tanning beds for any amount of time showed a 74-percent higher rate of melanoma than non-users, according to research published online May 27 in the journal Cancer Epidemiology, Biomarkers and Prevention.
That study did not investigate the percentage of indoor tanners who developed melanoma, rather showing the difference between users and non-users.
The UV light causes the DNA molecule thymine to bind to adjacent thymine molecules in a manner that renders both molecules unreadable during transcriptions, Santella said. Transcription is a step in which the body reads the DNA instructions the cell will later follow. When those thymine errors occur in areas of DNA that regulate cell growth, skin cancers like melanoma can begin to develop, Santella said.
Most times, skin cells rapidly repair most of those 40,000 errors, but over time repeated errors can cause cancer or other problems.
Endorphins are chemicals that transmit feelings of pleasure and happiness. In effect, exposure to UV radiation gets tanning bed users high, Feldman said. And like any high, tanning can become addictive.
In 2005, Feldman conducted a study where he gave volunteers endorphin-blocking chemicals before they used a tanning bed. The study aimed to test whether frequent tanning salon customers would enjoy the experience as much if their bodies didn't produce endorphins. They didn't. And even before the frequent tanners used the tanning bed, they showed signs of physical addiction to tanning.
"When we started doing the experiments, the first couple volunteers got sick, and we said 'Hey, that's unexpected,'" Feldman told LiveScience. "We were putting them into withdrawal."
Tan responsibly With studies proving that tanning bed use causes both addiction and cancer, many dermatologists have begun comparing the practice to other forms of drug abuse like drinking and cigarette smoking, Feldman said. And much like with smoking and drug abuse, doctors have told their tan-loving patients to "just say no."
"There is no point to it. Someone wants to look darker? Gimme a break. For cosmetic reasons, people risk getting a fatal cancer. To me, it's a public health hazard because it has no upside," Santella said. "Don't go to skin tanning salons. Simple as that."
"We see the cancer patients, but there are millions of people tanning, and considering the number of people doing it and not getting cancer, it's probably not the first problem we need to solve in America," Feldman said. "If a woman comes in, and I see cigarettes in her bag, I'll tell her to stop smoking before I tell her to stop tanning. Lung cancer is considerably worse."
But those approaches only tackle the physical side of tanning without getting to the root problem that drives millions of Americans, young women in particular, to engage in a behavior they often know raises their risk of a deadly disease, Stein said. To fix the social pressures behind the rise in this largely preventable cancer, America might need to refine its idea of beauty.