Sunburn Not Necessary for Skin Cancer
Even Moderate Amount of Sun Increases Melanoma Risk
WebMD News Archive
Feb. 14, 2003 -- You can predict your child's risk of
developing melanoma -- just count the number of moles you have on your arms.
And researchers have also found that even a moderate amount of sun exposure
during childhood -- no sunburn required -- significantly ups the risk of
melanoma, the deadliest form of skin cancer.
This finding comes as no surprise to dermatologist Ella L.
Toombs, MD, a former FDA medical officer. Though sun exposure has been
implicated as a major risk in other forms of skin cancer, how it affects
melanoma is not well known.
"However, recent research suggests that short bursts of sun
exposure -- especially to 'virgin' skin -- may somehow shock the system, making
skin even more vulnerable to later melanoma than more constant expsoure,"
she tells WebMD.
In the current study -- published in the Feb. 1 issue of
Cancer -- German researchers studied 1,800 nursery school children and
found that several factors seem to increase the number of moles in children as
they age -- including amount of sun exposure on a daily basis and during family
vacations, skin type and facial freckling, and even the number of moles on
their parents' arms.
But moderate sun exposure is closely tied to the appearance of
more moles, which may someday develop into melanoma, say the researchers.
Melanoma, which occurs when a mole develops into cancer, affects some 51,000
Americans each year and kills nearly 8,000 annually, according to the American
Academy of Dermatology.
In their study, the researchers at Ebergard-Karls University
say that children who spent at least three weeks on a family vacation in a
sunny climate were nearly twice as likely to develop melanoma -- and the risk
increased with longer vacation time.
Other factors that increased the risk of melanoma included:
- Playing outdoors -- Risk increased 1.5 times among children who
spent at least two hours playing outside each day.
- Moles on parents -- Risk increased 1.6 times when the mother had at
least 11 moles on her arms or the father had at least six. Risk tripled when
mothers had more than 51 moles.
- Freckles -- Risk tripled in children who had at least 30 freckles on
- Fair-skinned children -- As seen in previous studies, children who
were fair-skinned and had gray, blue, or green eyes had the greatest risk.
- Sunburn -- Interestingly, having just one sunburn as a child
increased the risk of melanoma, but the risk did not increase with additional
"That makes sense, based on recent research," says
Toombs. "What happens with sun exposure is a process called hardening --
basically, with repeated sun exposure, so much damage has been done that there
is no more that can be done. And with melanoma, we think that new exposed skin,
like that on the back while at the beach, is subject to greater trauma from
massive amount of sun in short bursts than skin that has been chronically