The ABC's of Skin Cancer

Skin cancer is the most common cancer in the United States, and is more common in Colorado than in most other states. This is because it is caused by exposure to radiation such as ultraviolet rays, found in our abundant sunshine and high altitude. Prevention of these cancers is mainly by limiting sun exposure, while treatment is improved if the cancer is caught early. Luckily, skin cancer is not one of the country's largest causes of mortality because several of the most common kinds of skin cancer don't readily metastasize, or spread to other organs of the body. However, all of them will grow and worsen until treated, and the type called melanoma can spread and cause an early death — an outcome all the more tragic because lesions can be seen easily on the skin, and can be cured and detected if treated early enough. It is also worth noting that the incidence of melanoma is steadily increasing in this country. Warning signs of possible melanoma include any of the following ABC's:

• Asymmetry of the mole's shape ( as opposed to round or oval spots)
• Borders that are blurry or jagged (rather than smooth or clearly defined)
• Color irregularities (not a uniform brown or skin tone)

In addition to irregularities of shape, border and color, a diameter larger than a 1/4" (the size of a pencil eraser), and elevation of the spot, especially if only part of the mole is raised and the other part is flat, increase the risk of a mole being melanoma. Unfortunately, some moles can have only a few of these characteristics and be melanoma, while others can have several of these clues and be benign. Luckily, most moles have none of these signs and are of little concern.

Basal cell and squamous cell carcinoma are two of the most common types of skin cancer, and often appear as painless sores that don't heal. They are rarely life threatening, but will continue to grow unless treated. An adult with a scab that does not heal for a month or two, especially if it has a raised smooth border to it, in a sun exposed area such as the face or arms, is a classic case of skin cancer until proven otherwise. People at the highest risk are those who burn easily, those who have had severe sunburn (even in their remote past), and those with a family history of skin cancer. These people should perform a periodic full body check, in front of a mirror with someone's assistance, to make sure they don't have "worrisome spots" — and every one should have their unusual moles rechecked by a doctor.

Richard Jacobi, M.D., is a family physician with Longmont Clinic.