The deadliest form of skin cancer has long been thought to be mainly a threat in late middle age and among men.
But diagnosis of melanoma has been on the rise at a younger age.
One new study suggests an alarming surge in melanoma among people in their 20s and 30s, particularly among women.
Researchers at the Mayo Clinic in Rochester, Minn., studied records of people in surrounding Olmstead County from 1970 through 2009, looking for first-time diagnosis of melanoma -- the deadliest form of skin cancer -- in patients ages 18 to 39.
They found 16 diagnoses of the cancer in the 1970s, 44 in the '80s, 67 in the '90s and 129 in the final decade. Over those four decades, the diagnosis rate among men rose fourfold, from 4.3 per 100,000 residents to 18.6. Among women, the rate shot up eightfold, from 5.4 to 43.5 cases per 100,000 residents.
The researchers, who published their findings in the April Mayo Clinic Proceedings, noted that the rates they found in Olmstead County were markedly higher than those seen in national cancer-surveillance surveys, particularly for women.
They said it's likely that the sharp increase is due to increased use of tanning beds by young women from their teens into middle age, and more sun exposure and sunburns among young people in general. They also note that young people may be paying closer attention to changes in their skin and asking health professionals about them. When tumors are detected early, before they've penetrated deep into the skin, the survival rate from melanoma is 99 percent, versus 15 percent with deep tumors.
Over a lifetime, melanoma risk is still higher among men than women, and most melanomas are diagnosed in white men over age 50. That's thought to be because men over 40 have the highest annual exposure to ultraviolet radiation from sunlight -- middle-aged men spend more time on the golf course or tending the lawn than younger men, while middle-aged women may be more wrinkle-conscious or simply more careful about sun protection than men.
While it was once thought most sun exposure came in youth, that's no longer accurate. In a 78-year lifespan, an individual would get about 23 percent of lifetime UV dosage by age 18 and another 23 percent by age 40, according to the Skin Cancer Foundation, a New York-based advocacy group involving dermatologists, researchers and sunscreen makers. Higher exposure comes with age -- 27 percent in the 40s and 50s, and the rest from age 60 on.
Despite ongoing efforts to discourage tanning-bed use by young adults and foster sun-safety practices from an early age, melanoma is the most common form of cancer among people in their late 20s.
Researchers continue to look for ways to communicate the danger.
One approach may be to show preteens their future risk for skin cancer via a UV photo.
A team at the University of Colorado demonstrated the technique in a study published in mid-March by the Journal of the American Academy of Dermatology.
The researchers recruited 585 12-year-olds to have UV, standard visible and cross-polarized photographs taken -- and then used a computer program to quantify sun damage observed on the photos. UV photos reveal spots on the skin -- undetectable on regular photos -- that indicate sun damage.
The researchers also noted the presence of known melanoma risk factors, such as pale skin color, facial freckling, red hair, blue eyes and a greater number of pigmented spots on the skin, such as moles.
The UV photos showed that children with the greatest sun damage also had the greatest number of melanoma risk factors.
By quantifying those risk factors and demonstrating damage already done through the UV photos, the researchers said they might be better able to motivate youngsters to avoid tanning beds, stay out of the midday sun and use protective clothing and proper sunscreen.
Contact Lee Bowman at BowmanL(at)shns.com.
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