There has been a dramatic rise in the most dangerous type of skin cancer cases in young adults, particularly in young women, a new long term study found. 

The findings show that the number of young adults with skin cancer have risen six times since the 1970s, and the number of women under 40 years old with cutaneous melanoma is now more than eight times the number of cases in the 1970sm and cases among men under 40 had also increased by more than four times 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 lead investigator Dr. Jerry Brewer, a Mayo Clinic dermatologist, in a news release.

Although men generally have a higher lifetime risk of developing melanoma, the findings show that the opposite is true for young adults and adolescents.  The study found that for every one male case, there are nearly two female cases in young adults aged 20 to 24.

Besides the incidence of childhood sunburns and ultraviolet exposure in adulthood, investigators said that some gender-specific behaviors which might explain why women may be affected the most by melanoma was because they are much more likely to use tanning beds or go sun tanning. 

"A recent study reported that people who use indoor tanning beds frequently are 74 percent more likely to develop melanoma, and we know young women are more likely to use them than young men," Dr. Brewer said.

Brewer added that despite the abundant information about the dangers of tanning beds, young women still continue to use them. 

"The results of this study emphasize the importance of active interventions to decrease risk factors for skin cancer and, in particular, to continue to alert young women that indoor tanning has carcinogenic effects that increase the risk of melanoma," Brewer said.

While there was in increased rate of skin cancer, the risk of dying from melanoma decreased by 9 percent a year over the same period, researchers reported.

The study, published in Mayo Clinic Proceedings, consisted of the overall number of melanomas diagnosed for the first time among people ages 18 to 39 from 1970 to 2009 in Olmsted County, Minnesota.  Researchers cautioned that the residents of the county were largely white and highly educated, which might not reflect the rest of the U.S. population, and the results may not apply to the whole nation. 

Janey Helland of Mapleton, Minnestoa, said she didn't think of the dangers when tanning in high school and college.

"I used tanning beds to get ready for homecoming and prom," she said in a statement released on Monday. "In college, I tanned before a trip to Barbados because I didn't want to get sunburned."

When she was 21, she noticed she had an abnormal spot on her leg, which turned out to be melanoma.  She said that the diagnosis changed her life.

"I really didn't know what my future was going to look like, or if I'd even have one," Helland said. 

Now, two years later, she is cancer-free and she dedicates herself to educating others. 

"I would advocate that it's better to be safe than sorry," she says. "My advice is to educate yourself and research the risk factors," she concluded.