About Skin Cancer

Skin cancer is the most common form of cancer in the United States. More than one million cases of skin cancer are diagnosed in the United States every year. In fact, it is estimated that 1 out of 7 people in the United States will develop some form of this cancer during their lifetime.

Skin cancer is a disease in which cancer (malignant) cells are found in the outer layers of your skin. Your skin protects your body against heat, light, infection, and injury. It also stores water, fat, and vitamin D. 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.

What Causes Skin Cancer?

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.