Skin cancer is the most common form of cancer in the United States. More than 500,000 new cases are reported each year, and the incidence is rising faster than any other type of cancer. While skin cancers can be found on any part of the body, about 80 percent appear on the face, head, or neck.

Who Gets Skin Cancer, and Why

The primary cause of skin cancer is ultraviolet radiation, most often from the sun. Other sources include sunlamps and tanning booths. In fact, researchers believe that our quest for the perfect tan, an increase in outdoor activities, and perhaps the thinning of the earth's protective ozone layer are behind the alarming rise in incidence in skin cancers.

Anyone can get skin cancer-no matter what your skin type, race or age, no matter where you live or what you do. But your risk is greater if:

• Your skin is fair and freckles easily.
• You have light-colored hair and eyes.
• You have a large number of moles, or moles of unusual size or shape.
• You have a family history of skin cancer or a personal history of blistering sunburn.
• You spend a lot of time working or playing outdoors.
• You live closer to the equator, at a higher altitude, or in any place that gets intense, year-round sunshine.
• You received therapeutic radiation treatments for adolescent acne.

Types of Skin Cancer

By far the most common type of skin cancer is basal cell carcinoma. Fortunately, it tends to grow slowly, and rarely spreads beyond its original site. Though basal cell carcinoma is seldom life-threatening, if left untreated it can grow deep beneath the skin and into the underlying tissue and bone, causing serious damage (particularly if it's located near the eye).

Squamous cell carcinoma is the next most common kind of skin cancer, frequently appearing on the lips, face, or ears. It sometimes spreads to distant sites, including lymph nodes and internal organs. Squamous cell carcinoma can become life threatening when left untreated.

A third form of skin cancer, malignant melanoma, is the least common, but its incidence is increasing rapidly, especially in Southern California. Malignant melanoma is also the most dangerous type of skin cancer. If discovered early enough, it can be completely cured. If it's not treated quickly, however, malignant melanoma may spread throughout the body and is often deadly.

Other Skin Tumors

Two other common types of skin growths are moles and keratoses.

Moles are clusters of heavily pigmented skin cells, either flat or raised above the skin surface. While most pose no danger, some, particularly large moles present at birth, or those with mottled colors and poorly defined borders, may develop into malignant melanoma. Moles are frequently removed for cosmetic reasons, or because they're constantly irritated by clothing or jewelry.

Solar or actinic keratoses are rough, red or brown, scaly patches on the skin. They are usually found on areas exposed to the sun, and sometimes develop into squamous cell cancer.

Recognizing Skin Cancer

Basal and squamous cell carcinomas can vary widely in appearance. The cancer may begin as small, white or pink nodule or bumps; it can be smooth and shiny, waxy, or pitted on the surface. It might appear as a red spot that's rough, dry, or scaly; a firm, red lump that may form a crust; a crusted group of nodules; a sore that bleeds or doesn't heal after two to four weeks; or a white patch that looks like scar tissue.

Malignant melanoma is usually signaled by a change in the size, shape, or color of an existing mole, or as a new growth on normal skin. Watch for the "ABCD" warning signs of melanoma:

• Asymmetry-a growth with unmatched halves;
   
• Border irregularity-ragged or blurred edges;
   
• Color-a mottled appearance, with shades of tan, brown, and black, sometimes mixed with red, white, or blue;
   
• Diameter- a growth more than 6 millimeters across (about the size of a pencil eraser), or any unusual increase in size.

The most important thing to remember is this: get to know your skin and examine it regularly, from the top of your head to the soles of your feet, and including your back. If you notice any unusual changes on any part of your body, feel free to come in for Dr. Bolitho to check it out.

Reconstructive surgery may be required following the removal of a skin cancer, as in this patient following near complete loss of his nose after removal of a basal cell carcinoma.