Skin Cancer: Skin Health

Content provided by the Faculty of the Harvard Medical School

Skin cancer

As a child, you probably never suspected that carefree days spent sunning and swimming could be a prelude to skin cancer. But those hours outdoors elevated your risk of developing skin cancer today. Experts estimate that by age 18, you've accumulated 85% of your lifetime exposure to ultraviolet rays.

Skin cancer is the most common cancer in the United States, diagnosed in more than one million Americans each year. Skin cancer causes about 10,000 deaths annually. Most are from melanoma, the most severe form of skin cancer, which has become far more common in recent decades as people have spent more leisure time outdoors. In most cases, skin cancer is not fatal, but it can be disfiguring. The good news is that with early detection and treatment, more than 90% of cases can be cured. The three major types of skin cancer (see Figure 3) are described below.

Figure 3: Three kinds of skin cancer Squamous cell cancer: Begins in the middle layer of the epidermis and affects only the surrounding area, but eventually forms a raised patch with a rough surface. Basal cell cancer: The cells of this type of cancer resemble the cells in the lowest layer of the epidermis, the basal layer. The cells invade and destroy surrounding tissues, forming a painless bump or nodule that later becomes an open ulcer with a hard edge. Malignant melanoma: The deadliest form of skin cancer occurs when melanocytes, pigment-making cells in the basal layer or in surface moles, begin reproducing uncontrollably, spreading to distant parts of the body.

Last updated:	July 20, 2007