What is Skin Cancer?

Cancer develops when DNA, the molecule found in cells that encodes genetic information, becomes damaged and the body cannot repair the damage. These damaged cells begin to grow and divide uncontrollably. When this occurs in the skin, skin cancer develops. As the damaged cells multiply, they form a tumor. Since skin cancer generally develops in the epidermis, the outermost layers of skin, a tumor is usually clearly visible. This makes most skin cancers detectable in the early stages.

Types of Skin Cancer

Three types of skin cancer account for nearly 100% of all diagnosed cases. Each of these three cancers begins in a different type of cell within the skin, and each cancer is named for the type of cell in which it begins. Skin cancers are divided into one of two classes - nonmelanoma skin cancers and melanoma. Melanoma is the deadliest form of skin cancer.

The different types of skin cancer are:
- Basal cell carcinoma (BCC)
- Squamous cell carcinoma (SCC)
- Melanoma
- Other nonmelanoma skin cancers: All other skin cancers combined account for less than 1% of diagnosed cases. These are classified as nonmelanoma skin cancers and include Merkel cell carcinoma, dermatofibromasarcoma protuberans, Paget's disease and cutaneous T-cell lymphoma.

Causes

Sun exposure is the leading cause of skin cancer. According to the American Cancer Society, "Many of the more than 1 million skin cancers diagnosed each year could be prevented with protection from the sun's rays." Scientists now know that exposure to the sun's ultraviolet (UV) rays damages DNA in the skin. The body can usually repair this damage before gene mutations occur and cancer develops. When a person's body cannot repair the damaged DNA, which can occur with cumulative sun exposure, cancer develops.

In some cases, skin cancer is an inherited condition. Between 5% and 10% of melanomas develop in people with a family history of melanoma.

Who Gets Skin Cancer?

Skin cancer develops in people of all colors, from the palest to the darkest. However, skin cancer is most likely to occur in those who have fair skin, light-colored eyes, blonde or red hair, a tendency to burn or freckle when exposed to the sun, and a history of sun exposure. Anyone with a family history of skin cancer also has an increased risk of developing skin cancer. In dark-skinned individuals, melanoma most often develops on non-sun-exposed areas, such as the foot, underneath nails, and on the mucous membranes of the mouth, nasal passages, or genitals. Those with fair skin also can have melanoma develop in these areas.

Skin Cancer Rates Rising

While Americans now recognize that overexposure to the sun is unhealthy, the fact remains that most do not protect their skin from the sun's harmful rays. As a result, skin cancer is common in the United States. More than 1 million nonmelanoma skin cancers are diagnosed each year, and approximately one person dies from melanoma every hour.

If current trends continue, 1 in 5 Americans will develop skin cancer during their lifetime. Melanoma continues to rise at an alarming rate. In 1930, 1 in 5,000 Americans was likely to develop melanoma during their lifetime. By 2004, this ratio jumped to 1 in 65. Today, melanoma is the second most common cancer in women aged 20 to 29.

Prevention and Early Detection Key

Sun protection can significantly decrease a person's risk of developing skin cancer. Sun protection practices include staying out of the sun between 10 a.m. and 4 p.m. when the rays are strongest, applying a broad-spectrum (offers UVA and UVB protection) sunscreen with a Sun Protection Factor (SPF) of 15 or higher year-round to all exposed skin, and wearing a protective clothing, such as a wide-brimmed hat and sunglasses when outdoors.

Since skin cancer is so prevalent today, dermatologists also recommend that everyone learn how to recognize the signs of skin cancer, use this knowledge to perform regular examinations of their skin, and see a dermatologist annually (more frequently if at high risk) for an exam. Skin cancer is highly curable with early detection and proper treatment.

Prevention

Most skin cancer can be prevented by practicing sun protection, according to numerous research studies. Research also shows that not only does sun protection reduce one's risk of developing skin cancer; sun protection also may decrease the likelihood of recurrence.

Even if you have spent a lot of time in the sun or developed skin cancer, it's never too late to begin protecting your skin. The American Academy of Dermatology (Academy) recommends that everyone protect their skin by following these sun protection practices:

Sun Protection Practices

1. Avoid deliberate tanning. Lying in the sun may feel good, but the end result is premature aging (wrinkles, blotchiness, and sagging skin) as well as a 1 in 5 chance of developing skin cancer. Tanning beds and sunlamps are just as dangerous because they, too, emit enough UV radiation to cause premature aging and skin cancer. If you like the look of a tan, consider using a sunless self-tanning product. These products do not protect skin from the sun, so a sunscreen should be used.

2. Get vitamin D safely through a healthy diet that includes vitamin supplements. Don't seek the sun.

3. Generously apply sunscreen to all exposed skin every day. The sunscreen should have a Sun Protection Factor (SPF) of at least 15 and be broad-spectrum (provides protection from ultraviolet A (UVA) and ultraviolet B (UVB) rays).

Dermatologists worldwide agree that the Australians' use of the word "slop!" accurately describes how sunscreen should be used. Most people do not apply enough sunscreen to help protect against harmful ultraviolet (UV) radiation. One ounce, enough to fill a shot glass, is considered by the Academy to be the amount needed to cover the exposed areas of the body properly. So when applying sunscreen, remember to "slop!" it on.

Here are a few more tips:

• Don't forget your ears, nose, neck, hands, and toes. Many skin cancers develop in these areas. Protect your lips, another high-risk area, with lip balm that offers sun protection with an SPF of 15 or higher.
• Sunscreen should not be used to prolong sun exposure. Some UV light gets through sunscreen.
• Sunscreens should be applied to dry skin 15-30 minutes before going outdoors, and reapplied every two hours.
• Be sure to reapply sunscreen after being in water or sweating.
• Sunscreen does not make sunbathing safe.

4. Wear protective clothing, such as a long-sleeved shirt, pants, a wide-brimmed hat, and sunglasses, where possible. This is what Australians call the "slip!" and "slap!" of sun protection. When you will be out in the sun, be sure to slip on protective clothing, such as a shirt, and slap on a wide-brimmed hat. Here's why:

• Clothing protects your skin from the sun's harmful rays. The tighter the weave, the more sun protection provided. In fact, clothing plays such an important role in sun protection that clothing designed specifically to protect against the sun as well as laundry additives created to boost clothing's protective function are available. Your dermatologist may be able to provide you with more information about these products.
• A wide-brimmed hat shades your face and neck from the sun's rays. Wide-brimmed means the brim circles the entire hat and shades both the face and neck.

5. Seek shade when appropriate. The sun's rays are strongest between 10 a.m. and 4 p.m.

6. Use extra caution near water, snow, and sand as they reflect the damaging rays of the sun. This can increase your risk chance of sunburn.

7. Check your birthday suit on your birthday. If you notice anything changing, growing, or bleeding on your skin, see a dermatologist. Skin cancer is very treatable when caught early.

More Good Reasons to Practice Sun Protection

Aside from skin cancer, the sun's UV rays also cause:

• Premature aging: Signs of premature aging include wrinkles, mottled skin, and loss of skin's firmness.
• Immunosuppression (weakening of the body's ability to protect itself from cancer and other diseases).
• Cataracts and macular degeneration: Macular degeneration, for which there is no cure, is the leading cause of blindness in people aged 65 and older.