The University of Minnesota says it's found a link between women who started indoor tanning at a young age and the rise in skin cancer.
In a study of skin cancer patients published Wednesday, the U found that younger women were two to six times more likely to develop melanoma – the deadliest form of skin cancer – if they had tanned indoors.
The study looked at 681 patients in Minnesota diagnosed with melanoma between 2004 and 2007, and 654 without skin cancer aged between 25 and 49-years-old.
It found that female melanoma patients under the age of 40 reported starting indoor tanning at a younger age (16 years old) than those aged 40-49 (25 years old) – and also tanned more frequently, averaging 100 sessions compared to 40.
"Younger women who tanned indoors experienced a 2.3- to 6-fold increase in the likelihood of developing melanoma; this relationship was particularly evident among women in their 20s," the report says.
One-third of the women diagnosed before the age of 30 had melanomas on their trunk (between their shoulders and hips), compared to one in four women aged 40 to 49.
All but two of the 63 of the women under 30 diagnosed with melanoma reported tanning indoors, and those who did had tanned on more than 10 occasions.
"Women in their 20s seemed to be at highest risk of developing melanoma from indoor tanning compared with any other age group of women or any age group of men because they initiated the behavior at the youngest age and reported a high median number of tanning sessions relative to their age," the report says.
"Given the substantial proportion of young women today who began indoor tanning as adolescents, this result is particularly concerning because their risk of developing melanoma in the future may be very high."
First of its kind study
The U of M said it's the first study to look at age and sex-specific links between indoor tanning and melanoma, having noted that incidences of the disease started rising more steeply in the mid-90s, with more younger female adults being diagnosed.
The World Health Organization in 2009 attributed in part to the use of indoor tanning, which it considers a human carcinogen, Web MD says.
According to SkinCancer.org, melanoma is the deadliest form of skin cancer. Its's cause when unrepaired DNA damage to skin cells caused by ultraviolet radiation (from the sun, or tanning beds) triggers mutations that lead to malignant tumors.
Melanomas resemble moles, with the majority black or brown, but can also be skin-colored, pink, red, purple blue or white. Melanoma affects just under 10,000 people in the U.S. each year.