| July Missouri Regional Newsletter p4 |
| How UV light causes cancer
"UV radiation seems to be the cause of all three common skin cancers�basal cell carcinoma, squamous cell carcinoma, and melanoma. It is thought to induce skin cancers by three mechanisms: First, ultraviolet light directly damages DNA, leading to mutations; second, it produces activated oxygen molecules that in turn damage DNA and other cellular structures; and third, it leads to a localized immunosuppression, thus blocking the body's natural anti-cancer defenses." �Skin Cancer Foundation "There's a whole tanning industry that's trying to promote ultraviolet exposure as a good thing and that�s a problem," said Martin Weinstock, MD, chair of the ACS Skin Cancer Advisory Group. In fair-skinned people, a tan provides about the same protection as a weak SPF4 sunscreen. "[T]he problem is in order to get that so-called base tan, they're getting UV radiation. And then if they go out in the sun later they're getting even more radiation than they would have gotten otherwise, because they would have been afraid of the sun," explained Weinstock. "There is no such thing as a safe tan," writes Dr. Shelley Sekula-Gibbs, MD, in an American Academy of Dermatology publication. "A tan is the skin's response to an injury, and every time you tan you accumulate damage to the skin, as well as accelerate the aging process and increase your risk for skin cancer." Scientists Uncover the Dark Side of UVA Light The main type of light used for indoor tanning, ultraviolet "A," does not produce a sunburn and until recently, it wasn't conclusively linked to skin cancer. But in March 2004, Australian scientists reported a dark side to UVA. Their findings were published in the Proceedings of the National Academy of Sciences. The team examined DNA from two types of skin cancer, and found evidence that UVA caused mutations (damage) deep in the basal layer, a critical part of the skin where new cells are made. UVB mutations were found in a more superficial layer of skin. Scientists knew that UVA reached deeper skin layers than UVB light, but thought it was less likely to damage cell DNA. Now it appears UVA rays can cause substantial damage . . . and damaged DNA can lead to cancer. Study authors suggested that people should change their habits to avoid overexposure to UVA radiation, whether it comes from the sun or an artificial source like a tanning bed. Check and Protect Your Skin The vast majority of skin cancers are preventable by routinely shielding your skin from the sun's damaging ultraviolet rays�both UVB and UVA. Yet the majority of Americans aren't doing enough to protect themselves. Bring your sun-protection habits in line with the recommendations below. How to a Skin Check ABCD Rule to Check Moles and Birthmarks Four Ways to Protect Your Skin Tips for Correct Use of Sunscreen The UV (Sunny Day) Forecast Beyond Suncreen Examine Your Skin Monthly Dermatologists recommend doing a skin check monthly, so you'll be more likely to notice small changes and to find a skin cancer when it's still small. People with darker skin tones, such as African-Americans, need to check their palms, fingernails, and feet carefully. The best time to examine your skin is after a shower or bath. Check yourself in a well-lit room using both a full-length and a hand-held mirror. Become familiar with your birthmarks, moles, and blemishes so you know what they usually look like and then can easily identify any changes they undergo. Signs to look for are changes in size, texture, shape, and color of blemishes or a sore that does not heal. If you find any changes, see your doctor or health care provider. Also, during regular checkups, ask your doctor to check your skin. |
| ACS NEWS |