Maintaining Your Health on Mackinac
Skin Cancer Can Strike Tanning Parlor Users
By Yvan Silva, M.D.

There has been an alarming increase in the rates of skin cancer in young people. The incidence of melanoma, the lethal type of skin cancer, has doubled in the United States from 30 years ago among young women ages 15 to 29. In this age group, it is estimated that 2,050 will be diagnosed with melanoma this year. This is a dramatic shift from a decade ago, when most dermatologists considered skin cancer a predominant occurrence in old people. Concerns have now shifted to the long term consequence of artificial tanning used by adolescents and young women, among others. There is concern that this spike in melanoma occurrence may be related to the increasing use of tanning parlors and the increased exposure to ultraviolet (UV) radiation. Just recently, the World Health Organization estimated that 60,000 deaths occur worldwide because of excessive exposure to UV radiation, and advised individuals under the age of 18 not to indulge in indoor tanning.

In 2004, 1.3 million or so Americans were diagnosed with skin cancer, and the resulting death rate was about 9,000. A recent survey showed that 13 percent of children, 12 years or younger, have experienced at least one episode of sunburn, and that 24 percent of parents admit they've never used sunscreen to protect their children. Studies have shown that 80 percent of the damage to skin has occurred in people before they're 18 to 20 years old. Five or more episodes of sunburn will double the risk of skin cancer, and that damage is lasting because it is cumulative, meaning the more you burn, the more the risk of cancer. Overall, the risk increases with aging because of the cumulative effects of sun exposure over time. In spite of public education, the increase continues. Screening programs have not had the intended results. Skin cancers when detected are not smaller in size as would be expected, and cancers are being found more commonly on the torso (most often, they occur in areas exposed to the sun like the head and neck), leading to the suspicion that artificial tanning may be involved.

The indoor tanning industry is a $5 billion-a-year business. Teenagers have become attracted to tanning in large numbers, and an estimated 2.3 million use a tanning parlor at least once a year. Many indulge as a rite of spring in readiness for proms, and other young people do so in

preparation for weddings and other public celebrations. The onsets of fall and impending winter in many parts of the country are also times when individuals seek tanning. A 2000 survey of 1,300 teenagers conducted by university researchers in a Midwest state found that 42 percent of the females in the group had tried indoor tanning.

There is emerging evidence that tanning, whether indoor or out, may be addictive. Tanning may trigger endorphins, which make the experience relaxing, and may explain why frequent tanners experience withdrawallike symptoms when they don't get their fix. A recent legal dispute brought against a tanning chain accuses the company of promoting UV lamps as a healthy alternative to outdoor tanning, likening a "safe" tan to a "safe" cigarette.

Sunburn in children occurs very frequently and is often quickly forgotten. Sunburn is particularly dangerous to children because their skin is thin and delicate. It may take only 10 to 15 minutes of exposure to the sun to burn a child's skin. Importantly, sunburn can occur on a cool and cloudy day even when the sun's rays don't seem to be hot or bright. The principles that apply to protection from sunburn are especially important in children - time and duration of exposure, clothing, UV-protected eyewear, and applications of waterproof sunscreen throughout the exposure.

The skin is the body's largest organ, a living envelope that protects from injury and infection and works for temperature regulation. The topmost layer, the epidermis, consists of cells that shed as younger ones develop in layers below them and grow outwards. Skin coloration is controlled by melanocytes that produce the pigment melanin. Sun exposure excites the production of increased melanin that creates the tanned appearance. The ensuing cell damage may cause newly formed cells to grow in a disorderly fashion to produce cancers in the skin.

There are three forms of ultraviolet (UV) rays from the sun. These wavelength bands, UVA, UVB, and UVC, must filter through the atmosphere's ozone layer to reach the earth. UVC is filtered out for the most part; ozone depletion may be responsible for increased UVA and UVB reaching us. UVB is the most damaging of the sun's burning rays. It is known to cause changes in the DNA of skin cells, leading to mutation of certain genes called oncogenes that induce malignant change. UVB rays are linked to sunburn that can result in squamous and basal cell cancers. They are not the sole cause. UVA is the second form of UV radiation. These rays penetrate deeper into the skin and weaken its immune system, setting the stage for cancers like melanoma. When damage to the melanocytes occurs, these cells may not be able to repair themselves, making them susceptible to cancer formation. Tanning beds run machines with high dose UVA; some of them also emit UVB. Intense exposure, although it may be occasional, poses a greater risk to melanoma than tanning in the sun.

Does all this mean that we should avoid the sun? Not really. While excessive exposure to UV radiation causes skin cancer, premature aging of skin, and cataracts, sunshine is helpful in the metabolism of calcium and bone. The body uses UV light in the synthesis of vitamin D, which is vital for bone health. But that is also available in fortified milk and vitamin-containing supplements. In most fairskinned individuals, sufficient skin exposure for this function is obtained in 10 to 15 minutes of sunshine to the face and arms. There is no reason to avoid having fun in the sun. Protection from harmful rays is foremost. When used properly, and that is as often as every two hours, the sunscreen product should have the proper Sun Protective Factor (SPF). SPF 15 will deflect 93 percent of the UVB rays. It does not matter if the product is waterproof or sweat-proof, what is important is that repeated applications are most protective. New broad-spectrum sunscreens are being developed to protect against UVA rays. They include substances like zinc oxide, titanium dioxide, and others. SPF protection is imperative at all times, including on cloudy days.

Indoor tanning is not any safer than sunbathing. When used in excess, the UVB rays cause sunburn, while excess of UVA predisposes to wrinkles - and both predispose to skin cancer. Spray-on tans and sunless tanning lotions are safe. They are often recommended by dermatologists. An active ingredient, dihydroxyacetone, attaches to the outer layer of skin and fades with normal exfoliation. They provide very little UV protection and should therefore be used in conjunction with sunscreen if there is going to be exposure to sun. People with dark skin do not possess any special protection. Although melanoma is more common in white populations, it can be fatal in Afro- Americans and Hispanics because the cancer may remain undetected longer.

If sunburn occurs, soak a cloth with cool water, wring it out, and apply directly to the burned area for 10 to 15 minutes three or four times a day. Bathing the area with a diluted mixture of baking soda in water will help soothe the skin. Apply a water-based moisturizer for comfort. Remember to rehydrate with plenty of fluids.

Indoor tanning has become an obsession. Teenagers are especially prone because of the social desirability and the feeling of well-being that seems to accompany a good tan. Tanning is not any safer than direct sunlight - both can be harmful when sunburn occurs. Children are particularly susceptible over the long term that skin cancer can develop. It may take only 10 to 15 minutes for a child to get sunburn.

Sunshine can be enjoyed, but proper protection from sunburn must be practiced. Sunscreen should be applied about 20 minutes before going outside in the sun. Sunscreen should be used and reapplied every 90 to 120 minutes during exposure and more often when swimming or sweating. The sun's rays are strongest between 10 a.m. and 3 p.m., and keeping out of direct sunlight during that time is recommended. Wear protective clothing that covers the body as much as possible. Wear UV-protected sunglasses. Sunscreen loses its effectiveness over time. Buy new sunscreen every year.

Dr. Silva is a professor of surgery at Wayne State University and a resident of Woodbluff on Mackinac Island.