A Cover Story: Skin Cancer Prevention

Planning for summer fun? Include an ounce of prevention in your plans regarding skin protection for yourself and your family. Skin cancer is the most common cancer - 1.3 million cases per year - almost 50 percent of all cancers. Basal cell is the most common skin cancer, with squamous cell the second most common. Both are much more common in Caucasians (about 10 times as common as in African Americans).

The most dangerous skin cancer, melanoma, accounts for a small proportion of all skin cancers, but incidence rates are increasing rapidly at a rate of about 4 percent per year. This is the greatest rate of increase among all cancers, except lung cancer in women. Long-term survival rates for melanoma are improving (95 percent when localized and about 88 percent overall). But prevention is still the best medicine.

To effectively prevent skin cancer, one must be aware of risk status and effective preventive measures. Risk factors for skin cancers of all types include both personal and environmental factors.

Personal factors are skin type (see table), various genetic syndromes such as Xeroderma Pigmentosa and dysplastic nevus syndrome. Also, people with suppressed immune systems - who have AIDS or who have had an organ transplant - are at an increased risk. So, too, are those who have a previous history of skin cancer. Like other cancers, skin cancer incidence increases with age.

Some occupations increase one's risk due to amount of exposure to the sun and other factors. Occupational exposure to coal tar, pitch, creosote, arsenic compounds or radium has been associated with the occurrence of skin cancer. Environmental factors include the geographic region of the world, with those having high levels of solar radiation presenting the highest risk.

Each individual has a different level of solar "dose" that is dangerous for them, based on skin type as well as other personal and environmental factors. For example, a person with Type III or IV skin who usually tans easily might still have an increased risk of skin cancer following a kidney transplant due to immunosuppressive medications, or if exposed to any of the above chemicals in the workplace.

The key to prevention is reducing exposure to avoidable risk factors by following the ABC's shown in the box. Sunscreens that block both UVA and UVB rays are desirable. However, the SPF primarily indicates UVB protection since no standard measure of UVA protection yet available.

Studies have shown that most people do not use an adequate amount of sunscreen - approximately an ounce (30cc) is needed to cover the average person and provide the SPF reported on the product label. While the shorter UVB rays are responsible for most sunburns, the longer UVA rays penetrate deeper skin layers, resulting in immediate and delayed tanning and can cause weak sunburns. The newest theories say UVA rays pose the greater risk of melanoma skin cancer. Tanning booths primarily emit UVA radiation.

Children and adolescents merit special attention as recent evidence indicates that the number of blistering or severe sunburns an individual receives prior to age 20 is related to the level of lifetime risk of skin cancer, particularly melanoma.

Screening for skin cancer is another level of protection. All individuals should be screened by a health professional at an interval based on their risk. Those at average risk who are less than 40 years of age can be screened at their regular health check-up, at least every three years. Those over 40, and those at high risk, should be screened more often. In addition, the American Cancer Society proposes a self skin exam (SSE) on a monthly basis as a way of "getting to know your body" and its various moles and other skin characteristics. SSE involves a comprehensive examination of all body surfaces, including the scalp, skin folds, soles of the feet, etc. A mirror should be used to examine the back or hard-to-see skin surfaces, or a partner can help to inspect the entire body.

Using the ABCDE rule (see box), moles or other skin lesions should be inspected for any changes. While African-Americans are less likely to develop skin cancer in general, the occurrence of melanoma in unusual areas, such as palms of hands or soles of feet makes a complete SSE and periodic HCP screening important for those of all racial groups.

Ongoing research into skin cancer prevention and treatment will lead to new and more effective sunscreens, increased knowledge regarding the mechanisms responsible for skin cancer occurrence and more effective treatment.

Topical and dietary use of retinoids, for example, is believed to hold promise for treatment of basal cell and dysplastic nevi. Beta carotene is being studied for its role in preventing recurrence of both basal and squamous cell skin cancers. More effective educational approaches to influence skin protection behaviors, particularly in adolescents, are also being studied. In the meantime, the smartest action to take this summer is to protect your skin - it will be your cover for a lifetime.

• Away from the sun between 10AM - 3PM. Remember UV rays come through clouds and are reflected off water, snow and other shiny surfaces. Avoid artificial tanning.
• Block UV rays using waterproof sunscreen of 15 SPF or higher. Use enough and reapply frequently. Remember that certain medications and medical conditions cause increased sensitivity to UV rays.
• Cover-up. Use special care to protect infants and children. Remember that wet clothing loses its ability to block UV rays.

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©2006 Texas Medical Center

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