NEW YORK, April 29 /PRNewswire/ -- Unlike most forms of cancer, skin
cancer is one of the few cancers where the cause of the majority of cases is
known -- excessive sun exposure. Despite this fact, there are still sun
worshippers who throw caution to the wind and ignore common sun-safe practices
such as wearing sunscreen, protective clothing, and avoiding the midday sun in
their quest for a tan. With this in mind, it's not surprising that more than
1 million new cases of skin cancer will be diagnosed in the United States this
year.
Speaking today at the American Academy of Dermatology's Melanoma/Skin
Cancer Detection and Prevention Month Press Conference, dermatologist
Vincent A. DeLeo, MD, Associate Professor of Clinical Dermatology, Columbia
University, New York, presented new research on sunscreens and lifetime sun
exposure that sheds new light on the importance of adopting a comprehensive
sun protection program throughout life.
Sunscreens
Sunlight consists of two types of harmful rays -- UVA rays and UVB rays.
The UVB rays are the sun's burning rays (which are blocked by window glass)
and are the primary cause of sunburn and skin cancer. UVA rays (which pass
through window glass) penetrate deeper into the dermis, or base layer of the
skin. The Sun Protection Factor (SPF) system currently used to rate the
strength of sunscreens measures their ability to provide primarily UVB
protection, which helps prevent sunburn.
But a sunscreen's SPF does not measure the amount of protection it
provides from UVA rays, which can cause immunosuppression -- or the weakening
of the body's ability to protect itself from cancer and other diseases. Since
UVA protection is not measured in a sunscreen's SPF rating, it is possible
that even though a person is getting adequate UVB protection to prevent
sunburn the UVA rays can still cause unseen damage below the skin's surface
that could cause skin cancer.
"Since UVA radiation can cause immunosuppression, it could explain why
some skin cancers appear anywhere on the body -- including places that are not
directly exposed to the sun," explained Dr. DeLeo.
Recent studies have demonstrated that broad-spectrum sunscreens (which
provide both UVB and UVA protection) with an SPF of 15 or higher, while
providing adequate UVB protection, may not have a corresponding level of UVA
protection. In fact, one new study demonstrated that the amount of protection
from immunosuppression caused by UVA rays that is obtained from the average
broad-spectrum sunscreen is more than 50 percent lower than its sunburning
protection unless separate UVA protective ingredients are used as additives.
"In order for a sunscreen to be fully effective, it must have enough UVA
protection to achieve the broad-spectrum coverage that is required to reduce
the immunosuppressive risk," said Dr. DeLeo. "To meet this challenge, it has
been proposed that sunscreens contain an IPF -- or Immune Protection Factor --
that would work similar to an SPF to adequately judge a sunscreen's efficacy."
"The good news stemming from this research is that there are sunscreens
currently being developed that are much more protective in the UVA range and
may soon be available in the United States," added Dr. DeLeo. "That's why in
the meantime, it's so important that people follow a comprehensive sun
protection program to supplement their use of sunscreen."
The American Academy of Dermatology recommends that everyone follow these
sun protection guidelines: Avoid outdoor activities between 10 a.m. and 4
p.m. when the sun's rays are the strongest; Seek shade whenever possible; Wear
a broad-spectrum sunscreen with a Sun Protection Factor (SPF) of 15 or higher;
Wear sun-protective clothing and accessories, such as wide-brimmed hats and
sunglasses; and Follow the "Shadow Rule" -- if your shadow is shorter than you
are, the sun's damaging rays are at their strongest and you are likely to
sunburn.
Lifetime Sun Exposure
Previous research has demonstrated that sun exposure prior to the age of
18 significantly increases the risk of developing skin cancer later in life,
particularly melanoma -- the deadliest form of skin cancer.
Now, new research has shown that sunburns after the age of 20 also
increase the risk of developing melanoma. One study of 1,263 melanoma
patients examined the amount of each person's cumulative sun exposure in
childhood and after age 20. The study found that persons with a history of
even one extensive sunburn after the age of 20 have a two-fold increased risk
for developing melanoma. Another study of 603 melanoma patients found that
people with five or more sunburns more than doubled their risk of developing
melanoma later in life, regardless of their age when the sunburns occurred.
The study points to a direct correlation between an increase in sunburns
throughout life and an increased risk of developing melanoma.
"These new findings are extremely important, because up until this point
sunburns that occurred later in life were not thought to be as detrimental as
those in childhood," said Dr. DeLeo. "People of all ages need to be vigilant
about protecting themselves from the sun and understand that the best
protection against skin cancer is avoiding prolonged periods of unprotected
sun exposure. As new research becomes available, I'm certain that we'll
continue to learn more ways to protect ourselves from skin cancer."
The American Academy of Dermatology, founded in 1938, is the largest, most
influential, and most representative of all dermatologic associations. With a
membership of over 14,000 dermatologists worldwide, the Academy is committed
to: advancing the diagnosis and medical, surgical, and cosmetic treatment of
the skin, hair and nails; advocating high standards in clinical practice,
education, and research in dermatology; supporting and enhancing patient care
for a lifetime of healthier skin. For more information, contact the AAD at
1-888-462-DERM or http://www.aad.org .
SOURCE American Academy of Dermatology
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Related links:
http://www.aad.org
CONTACT:
Karen Klickmann, +1-847-240-1735,
kklickmann@aad.org , Jennifer Allyn, +1-847-240-1730,
jallyn@aad.org , or Kristin Lubeck, +1-847-240-1743,
klubeck@aad.org , all of American Academy of Dermatology
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