July 10 (Bloomberg) -- Melanoma rates among young women in the U.S. soared 50 percent since the 1980s, a trend that has paralleled a rise in the use of tanning salons and time spent sunning on the beach, according to government figures.

The report in the Journal of Investigative Dermatology found the incidence of deadly skin cancer rose in women aged 15 to 39 while remaining stable in men. Although the study didn't pinpoint a cause for the increase in women, it coincided with more days spent tanning or burning in the sun, researchers said.

Melanoma is the most deadly form of skin cancer, diagnosed in 67,000 people in the U.S. each year and killing more than 11,000, according to the American Cancer Society. Despite public health efforts to reduce exposure to ultraviolet radiation, the main environmental cause of the disease, millions of Americans still seek light rays either at the beach, backyard or tanning beds, which are used more often by women than men.

``The findings suggest that the public education campaigns that have been conducted in the U.S. since the 1980s about the risks of melanoma from sun tanning may not have resulted in a reduction in melanoma rates among young women,'' said Mark Purdue, a research fellow at the National Cancer Institute in Bethesda, Maryland, in a telephone interview. ``We do seem to see some promising leveling off in the rates for young men.''

The results may indicate an even greater risk on the horizon, since melanoma may take years or decades to develop and turn deadly. The number of older people diagnosed with the disease has been rising for years, and researchers had hoped that prevention efforts would slow it in younger people.

Young and Tan

Kathryn Fleming, a 24-year-old Minneapolis waitress, said she often worries about skin cancer. Still, it's not enough to get her to stop weekly sessions in a tanning bed that are included in the cost of her fitness club membership.

``After destroying myself in the gym, I relax for 20 minutes,'' Fleming said in an interview. ``It's warm and I like the way it makes me look.''

Cynthia Brewer, a doctor in the Cleveland Clinic's Women's Health department in Ohio, said ``there's always a body image issue as far as our society goes.''

That focus on the body can cut both ways, she said. Women may be more likely to seek the sun and skip the sunscreen, and they also may be more likely to notice changes in their skin and go to the doctor for body checks and prevention, she said.

Proper sun exposure requires balance, Brewer said. She recommends patients get 10 minutes to 15 minutes of sun daily to ensure they produce enough vitamin D. For those interested in a tan, however, she recommends self-tanning lotion rather than direct ultraviolet light. The recommendations need to be altered for each individual patient, based on their risks, she said.

Additional Studies

Additional studies are needed to determine if sun exposure, either from being outside or in tanning beds, increases the risk of melanoma and accounts for some of the rise, researchers said.

Public health initiatives may increase awareness about the disease and help patients and doctors catch it early, said Joseph Levy, vice president of the International Smart Tan Network, an educational institute for North American tanning facilities. The number of dermatologists in the U.S. has risen by 85 percent since the 1980s, helping fuel detection, he said.

Deaths from the disease in people under age 39 haven't increased, and the fastest growing group for detection is men aged 50 and older, Levy said. Meanwhile, studies have linked vitamin D, which comes mainly from sunlight, to a host of health benefits for heart, cancer and kidney disease patients.

Men Over 50

``Men over 50 is where the public health message on this disease needs to be,'' Levy said in a telephone interview. ``At a time when people should be embracing regular exposure to sunlight, to suggest exposure to tanning in a non-burning fashion is somehow dangerous is irresponsible and unsupported by the existing data.''

In the study, the incidence of melanoma rose quickly for both young women and men between 1973 and 1980. The groups then separated, with 13.9 cases for every 100,000 women in 2004, up from 9.4 in 1980. The rate among men 39 and younger remained stable during the same period, at 7.7 per 100,000 people. The increase in women was seen with superficial lesions and the thicker, more advanced disease.

``The key piece of evidence suggesting that rates are truly going up is we're seeing an increase in the thicker lesions and later stage melanomas that are unlikely to be affected by the surveillance rates,'' Purdue said. ``It looks like the increase in incidence in young women we see is real.''

The next step is to see whether the changes in melanoma rates can be linked to changes in sun seeking behaviors in young women and men, helping explain the increases, Purdue said. While one possible explanation for the divergent findings is that young women are still getting unsafe sun exposure at a high rate, the theory is speculative, he said.

To contact the reporter on this story: Michelle Fay Cortez in Minneapolis at mcortez@bloomberg.net

Last Updated: July 10, 2008 12:18 EDT