The risk of developing the most dangerous type of skin cancer is now more than six times higher among young adults than it was 40 years ago, and women may be especially vulnerable.

A new study shows the number of melanomas found among women under 40 years old increased by more than eightfold between the 1970s and 2000s. Cases of melanoma among men under 40 also increased by more than fourfold during the same time period.

“We anticipated we'd find rising rates, as other studies are suggesting, but we found an even higher incidence than the National Cancer Institute had reported ... and in particular, a dramatic rise in women in their 20s and 30s," says researcher Jerry Brewer, MD, a Mayo Clinic dermatologist, in a news release.

Researchers say women may be hardest hit by melanoma because they are more likely to participate in activities that increase the risk of melanoma, such as using tanning beds or suntanning.

They say the findings are alarming, considering the rates of many other types of cancers are declining.

Sun-Damaged Skin: Sunburn, Melanoma and Other Reasons to Shun the Sun
Melanoma on the Rise

In the study, published in Mayo Clinic Proceedings, researchers looked at the number of melanomas diagnosed for the first time among people ages 18 to 39 from 1970 to 2009 in Olmsted County, Minn.

Overall, the results showed melanoma rates increased among men and women by more than sixfold during the study period.

The incidence of melanoma was eight times higher among young women and six times higher among young men in 2009 than in 1970.

Researchers say the dramatic rise in melanoma rates among the young is most likely due to increased use of tanning beds since 1970, as well as other unsafe exposures to ultraviolet light, such as severe sunburns in childhood.

While the study showed melanoma in young people is on the rise, researchers found deaths caused by this most deadly type of skin cancer actually declined in this group.

"People are now more aware of their skin and of the need to see a doctor when they see changes," says Brewer. "As a result, many cases may be caught before the cancer advances to a deep melanoma, which is harder to treat."
How to Prevent Melanoma

Researchers say the best way to reduce the risk of melanoma and other types of skin cancer is to limit exposure to ultraviolet radiation from tanning beds or the sun.

“A recent study reported that people who use indoor tanning beds frequently are 74% more likely to develop melanoma," says Brewer.

Other ways to protect your skin and reduce the risk of melanoma and other skin cancers include: 

    Stay out of the sun during peak hours: 10 a.m. to 4 p.m.
    Wear protective clothing with a tight weave, including a hat with a brim to shade your ears and neck, a shirt with sleeves to cover your arms, and pants.
    Use a sunscreen every day with an SPF of at least 30. Choose a sunscreen that protects against both types of ultraviolet radiation, UVA and UVB.
    Examine yourself regularly for changes on your skin, such as new moles or changes to old moles, and talk to your doctor about having a skin exam done by a health care professional.