Burden of Skin Cancer

The number of skin cancer cases has increased in the United States. More than 1 million cases of basal cell or squamous cell cancer will be diagnosed annually. In 2002*, the most serious form of skin cancer, malignant melanoma, was diagnosed in 44,582 persons and 7,513 men and women died of the disease, according to the United States Cancer Statistics: 1999–2002 Incidence and Mortality Report. Since 1981, the incidence of melanoma has increased a little less than 3 percent per year. Melanoma is the most common cancer among people 25 to 29 years old.

The three major types of skin cancer are basal cell carcinoma, squamous cell carcinoma, and melanoma.

Basal cell and squamous cell carcinomas can cause substantial illness and, if untreated, can cause considerable damage and disfigurement. If detected and treated early, however, these carcinomas have a cure rate of more than 90%.

Malignant melanoma causes more than 75% of all deaths from skin cancer. This disease can spread to other organs, most commonly the lungs and liver. Malignant melanoma diagnosed at an early stage usually can be cured, but melanoma diagnosed at a late stage is more likely to spread and cause death.

Exposure to the sun's ultraviolet (UV) rays appears to be the most important environmental factor in developing skin cancer. This makes skin cancer a largely preventable disease when sun protective practices and behaviors are consistently applied and utilized. UV radiation is also a factor in the development of lip cancer, making sun protection even more important. UV rays from artificial sources of light, such as tanning beds and sun lamps are just as dangerous as those from the sun, and should also be avoided. Unfortunately, despite the fact that both tanning and burning can increase one's risk of skin cancer, most Americans do not protect themselves from UV rays.

Acknowledgements for the Above Content: U.S. Cancer Statistics Working Group. United States Cancer Statistics: 1999–2002 Incidence and Mortality Web-based Report. Atlanta: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Cancer Institute; 2005.

• heredity - people with a family history of skin cancer are generally at a higher risk of developing the disease. People with fair skin, and a northern European heritage, appear to be most susceptible.
  
  
• environment - due to a reduction of ozone in the earth's atmosphere, the level of UV light today is higher than it was 50 or 100 years ago. Ozone serves as a filter to screen out and reduce the amount of UV light that we are exposed to. With less atmospheric ozone, a higher level of UV light reaches the earth's surface.

Other Factors:

• multiple nevi (moles) or atypical nevi.
  
  
• occupational exposure to coal tar, pitch, creosote, arsenic compounds, or radium.
  
  
• elevation - ultraviolet light is stronger as elevation increases (because the thinner atmosphere at higher altitudes cannot filter UV as effectively as it does at sea level).
  
  
• latitude - the rays of the sun are strongest near the equator.
  
  
• cloud cover - places with regular cloud cover may actually reduce UV -- resulting in a 50 percent lower level of UV light.
  

Who Is at Risk?
Although anyone can get skin cancer, individuals with certain risk factors are particularly at risk. Some risk factors for skin cancer are

• Lighter natural skin color
• Family history of skin cancer
• Personal history of skin cancer
• Constant exposure to the sun through work and play
• A history of sunburns early in life
• Skin that burns, freckles, gets red easily, or becomes painful in the sun
• Blue or green eyes
• Blond or red hair
• Certain types and a large number of moles

How can skin cancer be prevented?

The American Academy of Dermatology (AAD) recommends the following preventive steps: 

Wear protective clothing, including a hat with a four-inch brim.

Apply sunscreen all over your body and avoid the midday sun from 10 a.m. to 4 p.m.

Regularly use a broad-spectrum sunscreen with an SPF of 15 or higher, even on cloudy days.

The following six steps have been recommended by the AAD and the Skin Cancer Foundation to help reduce the risk of sunburn and skin cancer.

1. Minimize exposure to the sun at midday -- between the hours of 10 a.m. and 3 p.m.

• Apply sunscreen, with at least a SPF-15 or higher that protects against both UVA and UVB rays, to all areas of the body that are exposed to the sun.
  
  
• Reapply sunscreen every two hours, even on cloudy days. Reapply after swimming or perspiring.
  
  
• Wear clothing that covers the body and shades the face. Hats should provide shade for both the face and back of the neck. Wearing sunglasses will reduce the amount of rays reaching the eye by filtering as much as 80 percent of the rays, and protecting the lids of our eyes as well as the lens.
  
  
• Avoid exposure to UV radiation from sunlamps or tanning parlors.
  
  
• Protect children. Keep them from excessive sun exposure when the sun is strongest (between 10 a.m. and 3 p.m.), and apply sunscreen liberally and frequently to children 6 months of age and older.
  
  Do not use sunscreen on children under 6 months of age -- instead severely limit their exposure to the sun.

Remember, sand and pavement reflect UV rays even under the umbrella. Snow is even a particularly good reflector of UV rays. Reflective surfaces can reflect up to 85 percent of the damaging sun rays.

• SPF 15 sunscreen may absorb more than 92 percent of UVB radiation.
  
  
• SPF 30 sunscreen may absorb 96.7 percent.
  
  
• SPF 40 sunscreen may absorb 97.5 percent of UVB radiation.

What does SPF mean?
SPF value of a sunscreen is defined as the ratio of the energy required to produce a minimal erythema dose (skin reddening or minimal sunburn) through the sunscreen, compared to the energy required to produce the same reaction in the absence of the sunscreen.

For example, an individual who burns after 30 minutes of sun exposure could, in theory, extend the period of time until a burn begins to two hours with an SPF 4 sunscreen. However, the same person using a sunscreen with an SPF of 30 (15 hours of theoretical burn protection) may not in fact be protected from UV-induced erythema for an entire day of continuous sun exposure.

What about the chemicals in sunscreens?
The majority of the commercially available sunscreens today are a combination of agents from several chemical groups.

• Para-aminobenzoic acid (PABA) was an early chemical sunscreen agent frequently associated with contact and sun-contact sensitivity reactions, had poor consistency, and often discolored clothing. It is rarely found in sunscreens today.

• Para-aminobenzoic acid esters (primarily octyl dimethyl para-aminobenzoic acid) are commonly used in many sunscreens and have not been associated with the problems of PABA.

• Other sunscreen agents include compounds from these groups:

• salicylates - these are weak UV absorbers, but are highly water insoluble and sensitivity is rare. The most widely used salicylates are homosalate and octyl salicylate. Salicylates are considered to be among the safest sunscreens, even when used in high concentrations.

• cinnamate

• benzophenone

• anthranilate

• dibenzoylmethane

How to use sunscreens:
A sunscreen protects from sunburn and minimizes suntan by reflecting UV rays. Information in the parentheses refers to the UV Index.

• Use of a sunscreen with SPF of 20 to 30 offers substantial protection from sunburning and usually permits no tanning. (for Index 7 and above)

• Choose a broad spectrum sunscreen that filters out UVA and UVB. (for Index 3 and above)

• A sunscreen that provides an SPF under 4 offers the least protection. If you rarely burn and always tan this level of skin protection may be sufficient to help prevent burning and uneven coloration. (for Index 3 and above)

• High SPF sunscreens protect from burning for longer periods of time than do sunscreens with lower SPFs. (for all index levels)

• Apply sunscreens to all exposed areas of skin including those easily overlooked areas such as the rims of the ears, the lips, the back of the neck, and the feet. (for Index 3 and above)

• Sunscreens are recommended for everyone (over six months of age) because all skin types need protection from solar ultraviolet rays. Lighter skin types are at the greatest risk of developing skin cancer; but all people are at some risk. Wrinkling, toughening, and aging will happen to all skin types. (for Index 7 and above)

• Apply sunscreen liberally. Recommended dose is 1 ounce per application. Reapply every two hours, after being in the water, or after exercising or sweating. Incidental time in the sun could add up to a sunburn. Don't forget the time spent walking your dog, window shopping, or jogging on your lunch hour. (for Index 7 and above)

• Don't forget the sunscreen when performing outdoor chores. (for Index 3 and above)

Treatments for Skin Cancer

Treatment for skin cancer:
Specific treatment for skin cancer will be determined by your physician based on:

• your age, overall health, and medical history
• extent of the disease
• your tolerance for specific medications, procedures, or therapies
• expectations for the course of the disease
• your opinion or preference

There are several kinds of treatments for skin cancer, including the following:

• surgery
  Surgery is a common treatment for skin cancer -- used about 90 percent of the time, and often includes the following procedures:
• cryosurgery - freezing the tumor, which kills cancer cells.
• electrodesiccation and curettage - burning the lesion and removing it with a sharp instrument.
• grafting - uses a skin graft to replace skin that is damaged when cancer is removed.
• laser therapy - using a narrow beam of light to remove cancer cells.
• Mohs micrographic surgery - removing the cancer and as little normal tissue as possible. During this surgery, the physician removes the cancer and then uses a microscope to look at the cancerous area to make sure no cancer cells remain.
• simple excision - cutting the cancer from the skin along with some of the healthy tissue around it.

• radiation therapy
  Radiation therapy uses a radiation machine that emits x-rays to kill cancer cells and shrink tumors.

• electrochemotherapy
  Electrochemotherapy uses a combination of chemotherapy and electrical pulses to treat cancer.

• Other types of treatment include:
• chemotherapy - treatment with drugs to destroy cancer cells.

• topical chemotherapy - chemotherapy given as a cream or lotion placed on the skin to kill cancer cells.

• systemic chemotherapy - chemotherapy taken by pill, or needle injection into a vein or muscle.

• biological therapy (sometimes called biological response modifier (BRM) therapy, or immunotherapy)
  Biological therapy tries to get your own body to fight cancer by using materials made by your own body, or made in a laboratory, to boost, direct, or restore your body's natural defenses against disease.

• photodynamic therapy
  Photodynamic therapy uses a certain type of light and a special chemical to kill cancer cells.

• immunotherapy
  Immunotherapy of melanoma involves injecting a medication (called interferon) to boost the body's own immune system, helping it to slow the growth of the cancer.

A word about Indoor Tanning

"Tan indoors with absolutely no harmful side effects"
"No burning, no drying, and no sun damage"
"Unlike the sun, indoor tanning will not cause skin cancer or skin aging"

Beware of claims like these. Ads that claim indoor tanning devices are a safe alternative to outdoor tanning may be false.

Tanning indoors damages your skin. That’s because indoor tanning devices emit ultraviolet rays. Tanning occurs when the skin produces additional pigment (coloring) to protect itself against burn from ultraviolet rays. Overexposure to these rays can cause eye injury, premature wrinkling of the skin, and light-induced skin rashes, and can increase your chances of developing skin cancer.

Tanning Devices
The most popular device used in tanning salons is a clamshell-like tanning bed. The customer lies down on a Plexiglas surface as lights from above and below reach the body.
Many older tanning devices used light sources that emitted shortwave ultraviolet rays (UVB) that actually caused burning. Aware of the harmful effects of UVB radiation, salon owners began using tanning beds that emit mostly longwave (UVA) light sources. Some salons claim this is safe. While UVA rays are less likely to cause burning than UVB rays, they are suspected to have links to malignant melanoma and immune system damage.

Advertising Claims

Here are some claims commonly made about indoor tanning — and the facts.

"You can achieve a deep year-round tan with gentle, comfortable, and safe UVA light."
Ultraviolet light is divided into two wavelength bands. Shortwave ultraviolet rays called UVB can burn the outer layer of skin. Longwave ultraviolet rays called UVA penetrate more deeply and can weaken the skin’s inner connective tissue.
Long-term exposure to the sun and to artificial sources of ultraviolet light contributes to the risk of developing skin cancer. Two types of skin cancer, basal cell and squamous cell, are treatable if detected early. Melanoma, another type of skin cancer, can be fatal.

"No harsh glare, so no goggles or eye shades are necessary."
Studies show that too much exposure to ultraviolet rays, including UVA rays, can damage the retina. Overexposure can burn the cornea, and repeated exposure over many years can change the structure of the lens so that it begins to cloud, forming a cataract. Left untreated, cataracts can cause blindness.
The Food and Drug Administration requires tanning salons to direct all customers to wear protective eye goggles. Closing your eyes, wearing ordinary sunglasses, and using cotton wads do not protect the cornea from the intensity of UV radiation in tanning devices.
Long-term exposure to natural sunlight also can result in eye damage, but in the sun, people generally are more aware that their eyelids are burning. Under indoor UV lights, exposed skin remains cool to the touch. In addition, the intensity of lights used in tanning devices is much greater — and potentially more damaging to the eyes — than the intensity of UV rays in natural sunlight.

"Tan year round without the harmful side effects often associated with natural sunlight."
Exposure to tanning salon rays increases the damage caused by sunlight. This occurs because ultraviolet light actually thins the skin, making it less able to heal.
Unprotected exposure to utltraviolet rays also results in premature skin aging. A tan is damaged skin that is more likely to wrinkle and sag than skin that hasn’t been tanned. Over time, you may notice certain undesirable changes in the way your skin looks and heals. According to some skin specialists, skin that has a dry, wrinkled, leathery appearance early in middle age is a result of UV exposure that occurred in youth.

"No danger in exposure or burning."
Whether you tan indoors or out, studies show the combination of ultraviolet rays and some medicines, birth control pills, cosmetics, and soaps may accelerate skin burns or produce painful adverse skin reactions, such as rashes. In addition, tanning devices may induce common light-sensitive skin ailments like cold sores.

Protecting Yourself
1. Limit your exposure to avoid sunburn. If you tan with a device, ask whether the manufacturer or the salon staff recommend exposure limits for your skin type. Set a timer on the tanning device that automatically shuts off the lights or somehow signals that you’ve reached your exposure time. Remember that exposure time affects burning and that your age at the time of exposure is important relative to burning. Studies suggest that children and adolescents are harmed more by equivalent amounts of UVB rays than adults. The earlier you start tanning, the earlier skin injury may occur.

2. Use goggles to protect your eyes. Ask whether safety goggles are provided and if their use is mandatory. Make sure the goggles fit snugly. Check to see that the salon sterilizes the goggles after each use to prevent the spread of eye infections.

3. Consider your medical history. If you are undergoing treatment for lupus or diabetes or are susceptible to cold sores, be aware that these conditions can be aggravated through exposure to ultraviolet radiation from tanning devices, sunlamps, or natural sunlight. In addition, your skin may be more sensitive to artificial light or sunlight if you use certain medications — for example, antihistamines, tranquilizers or birth control pills. Your tanning salon may keep a file with information on your medical history, medications, and treatments. Make sure you update it as necessary.

A Word about Sunscreens
Chances are you spend some time in natural sunlight. You still could benefit from using sunscreens with sun protection factor (SPF) numbers of 15 or more. The SPF number gives you some idea of how long you can stay in the sun without burning. For example, if you normally burn in 10 minutes without sunscreen, you should be protected from burn for 150 minutes using SPF 15. Swimming and perspiration reduce the actual SPF value for many sunscreens, so be sure to reapply even if the product is water-resistant.

While all sunscreens provide some level of protection against UVB rays, no product screens out all UVA rays. Some may advertise UVA protection, but there’s no system yet for rating UVA protection. Even when you use a sunscreen with a high SPF number, there’s no way to know how much UVA protection you’re getting.

Regulation

The Food and Drug Administration (FDA) and the Federal Trade Commission (FTC) share responsibilities in the regulation of sunlamps and tanning devices. The FDA enforces regulations that deal with labels on the devices; the FTC investigates false, misleading, and deceptive advertising claims about the devices. When these agencies determine that device labels don’t comply with the regulations or that advertisements are not truthful, they may take corrective action. The FDA also can remove products from the marketplace.

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