There are more than 3 million cases of skin cancer in the United States each year. The incidence has increased at such a fast pace that now over half of all new cancers are skin cancers. The most common type is basal cell carcinoma, which accounts for 80% of all cases of skin cancer. Squamous cell carcinoma is the next most frequent form and represents about 16% of the total. Malignant melanoma, also referred to simply as melanoma, is the third most common type of skin cancer, accounting for about 4% of all skin cancers. Each of these three forms of skin cancer is distinct, and one type does not transform into another type. Almost all cases of skin cancer are related to excessive exposure to ultraviolet light (e.g., sunlight) and are more prevalent in fair-skinned individuals.
There is even an association between the incidence of skin cancer and latitude, with there being more cases in the southern United States due to the longer warm, sunny season. Advancing age is a risk factor for skin cancer, but all types of skin cancer can occur at almost any age.
Basal cell carcinoma and squamous cell carcinoma, the so-called “non-melanoma skin cancers,” are not usually life-threatening and can be cured with early detection and treatment. Melanoma is a much more serious type of skin cancer because of its potential for aggressive growth and metastasis (spread to other bodily sites).
In order to reduce the chances of developing a skin cancer, it is important to minimize direct exposure to ultraviolet light as much as possible. Helpful measures include wearing protective clothing and a wide-brimmed hat as well as avoiding the outdoors during the hours of 10 AM and 4 PM when the sun’s intensity is the highest. A sunscreen with a sun protection factor (SPF) of at least 30 should be liberally applied to all exposed skin, including the tops of the ears, every morning. It is also important to remember to reapply a layer of sunscreen every one to two hours during periods of direct exposure. Although most of the damage done by the sun occurs during childhood prior to the age of 18, it is never too late to begin a program of sun protection. Even individuals who have had numerous skin cancers can reduce their future risk by following these helpful measures. Studies have shown that individuals who have a personal history of skin cancer are at very high risk for the development of other skin cancers.
It is recommended that patients at risk for skin cancer undergo a skin screening examination by a dermatologist at least once a year. We also recommend monthly self-examinations at home to check for skin cancer. Screening efforts are especially important in individuals with a history of significant sun exposure, those who have previously had skin cancer, and people who have a family history of skin cancer.