Skin Cancer Cases, Often Preventable, Are On The Rise

It’s hard to believe that something that feels so good, so healthy, so restorative, can be so bad for us. Unfair as it may seem, spending time in the sun increases our risk for the most common cancer in the United States. It gives us wrinkles and makes our skin sag.

A tan – your body's attempt to protect itself from the sun's damaging rays – is actually nature’s way of telling you you’ve already had more than enough.

There are three main types of skin cancer. Melanoma, the least common but most serious, is responsible for three-quarters of annual US skin cancer deaths. This year almost 9,800 Americans will die of skin cancer – 7,400 of them from melanoma. The other two types, basal cell carcinoma and squamous cell carcinoma, are often referred to together as non-melanoma skin cancer. Basal cell carcinoma is by far the most common skin cancer, followed by squamous cell carcinoma. According to the American Cancer Society, “Most non-melanoma skin cancers develop on sun-exposed areas of the body, like the face, ear, neck, lips, and the backs of the hands.”

Easy to Avoid and Usually Treatable
Skin cancer is largely preventable, simply by avoiding sun and sunlamp exposure. Yet the number of skin cancer cases keeps growing. The American Cancer Society says that since 1973, the incidence rate of melanoma has increased about 4% every year. As recently as 1995, the ACS reported approximately 800,000 new cases of non-melanoma skin cancer. In 2001, that number had risen to more than 1 million new cases.

The incidence of malignant melanomas is also increasing: in 1995 the ACS predicted about 34,100 new cases. In 2001, that number had risen to 51,400. This year, the number of new of malignant melanoma cases is expected to reach 53,600.

David Allen, MD, chief dermatology resident at the Medical College of Wisconsin, notes: “In the 1930s, only 1 American in 1,500 developed invasive melanoma every year. By 1960, it had risen to 1 in 600. Today, it’s 1 in 66.” The National Cancer Institute now estimates that 1 out of 7 people in the United States will develop some form of skin cancer in their lifetime.

Why the increase? Dr. Allen cites two factors: Americans are spending more time outdoors without protecting their skin, and the decreasing natural ozone layer in the earth’s atmosphere has allowed more damaging ultraviolet (UV) sun rays to get through. Ozone serves as a filter that screens out and reduces the amount of UV light. The level of UV light we are exposed to today is higher than it was 50 or 100 years ago. Most scientists blame human activity – particularly the burning of fossil fuels – for producing gases that erode the ozone layer and produce a greenhouse effect.

The good news is that more than 90% of skin cancers are curable if treated early through surgical removal.

It’s Up to You to Shelter Your Skin
Based on consumer surveys, the FDA has estimated that only 2 in 5 people consistently use sunscreen whenever they're in the sun. “People want to enjoy the outdoors, but if they refuse to protect their skin, they could pay a high price later on,” Dr. Allen says, adding that the changing climate demands that patients take more responsibility than ever to protect themselves and their children from the sun’s damaging rays. To help prevent skin cancer, he recommends these steps:

• Use sunscreen whenever you will be exposed to the sun.
• Look for a product that lists an SPF (sun protection factor) of 30 or higher.
• Use products that provide broad-spectrum UV coverage and block both UVA and UVB light. One ingredient to look for is Parsol 1789 (butyl methoxydibenzoylmethane; also called avobenzone), which is highly effective at protecting against both UVA and UVB rays. Zinc oxide and titanium dioxide also effectively protect against both types of UV rays. A product listing only an SPF indicates its ability to protect against UVB light, not UVA. Despite widespread belief – and the marketing promises of some tanning salons – there are no "safe" UV rays. Although UVB rays are more carcinogenic, UVA rays can also damage skin and promote development of skin cancer.
• Apply sunscreen 30 minutes before going out in the sun. If you’re going in the water or if you perspire a lot, use a waterproof sunscreen. Apply sunscreen to all areas of the body that will be exposed to the sun, not just the face, shoulders and neck. Don’t forget about both sides of arms and legs, exposed scalp and back.
• Reapply sunscreen frequently, at least every two to three hours, more often if you sweat a lot or get in the water.
• Protect yourself even more with a wide-brimmed hat, long sleeves and sunglasses. Most fabrics don’t completely protect the wearer against radiation damage from the sun. However, special sun-protective clothing is available and highly effective.
• When possible, avoid outdoor activities during the hottest hours of the day, usually between 10 a.m. and 2 p.m.
• Adopt smart health habits – like quitting smoking – to further protect your skin. “Smoking ages skin much more quickly,” Dr. Allen says.

Protecting Children Is Critical
“Infants should be kept out of direct sun, because their skin is quite thin,” says Dr. Allen. “Once children are old enough to crawl, parents should apply sunscreen in lotion or spray form.”

Protecting children from sunburn, especially severe sunburns that blister, helps reduce one of the chief risk factors of melanoma, he says. According to the US Food and Drug Administration, skin cancer is striking Americans at ever-younger ages. One-quarter of the people expected to develop melanoma this year will be 39 or younger.

In addition, Dr. Allen warns that people with any of the following risk factors may have an even greater chance of developing melanoma:

• Having a close family member with melanoma
• Having a tendency to sunburn easily
• Having blue eyes, blonde or red hair, and/or a light complexion. Incidence rates of melanoma are 40 times greater for Caucasians than it is for darker-skinned people.
• Having a large number of moles, a changing mole or moles that bleed
• Belonging to an upper socioeconomic status

Exercise Special Caution If You Use Certain Drugs
Some medications make people even more sensitive to the sun’s harmful rays, Dr. Allen warns. “Patients using certain medications should be particularly careful about sun exposure.” Read the patient instructions carefully when you start a new medication – especially regarding sun exposure – or ask your health care provider or pharmacist about any additional risk.

Just as children are especially sensitive to the hazards of sun exposure, so are older Americans, he adds. Other special risks are living in or visiting more southerly climates or higher altitudes, where the sun’s intensity is greater, even in winter. People who work outdoors should take daily precautions, even on cloudy days.

What to Look For – the ABCDs of Skin Cancer
Once skin cancer develops, early detection and treatment are your best defense. Perform monthly skin self-exams so you get familiar with your skin and your own pattern of moles and freckles. If any growth, mole or discoloration appears suddenly or begins to change, or if a sore appears that doesn't heal, see a dermatologist, Dr. Allen advises. He suggests looking for the ABCDs:

1. Asymmetry – Any mole that is irregularly shaped (its two halves are not mirror images).
2. Border – A mole with a border that’s jagged, not smooth.
3. Color – A normal mole is usually uniform in color. A malignant mole might be white, red, blue or black.
4. Diameter – Any mole that is larger than 5 millimeters, or about the size of a pencil eraser.

Skin cancer is slow to develop. A one-day sunburn may take 20 years or more to become skin cancer – and just one serious sunburn can increase the risk by as much as 50%. “Some people think if you have a tan, that itself will protect you,” says Dr. Allen. “It won’t. The best tan is no tan.” If you must have a tan, he says, use “tan in a bottle” These products are cosmetically acceptable and don’t cause skin cancer.

Barbara Abel
HealthLink Contributing Writer

This article includes information from the Medical College of Wisconsin Department of Dermatology, the American Cancer Society, and the US Food and Drug Administration.

MCW Health News presents up-to-date information on patient care and medical research by the physicians of the Medical College of Wisconsin.