Skin Cancer

What is Skin Cancer?

Cancer develops when DNA, the molecule found in cells that encodes genetic information, becomes damaged and the body cannot repair the damage. These damaged cells begin to grow and divide uncontrollably. When this occurs in the skin, skin cancer develops. As the damaged cells multiply, they form a tumor. Since skin cancer generally develops in the outermost layers of skin, a tumor is usually clearly visible allowing cancers to be detected in the early stages.

Types of Skin Cancer: Three types of skin cancer account for nearly 100% of all diagnosed cases. Each of these three cancers begins in a different type of cell within the skin and each cancer is named for the type of cell in which it begins. Skin cancers are divided into one of two classes – nonmelanoma skin cancers and melanoma. Melanoma is the deadliest form of skin cancer.

The different types of skin cancer are:

Basal cell carcinoma (BCC): This is the most common cancer in humans developing in more than 1 million people in the United States per year. Approximately 80% of all skin cancers are BCC which is a cancer that develops in the basal cells which are the lowest layer of skin cells in the epidermis. These tumors tend to grow slowly and rarely spread to other parts of the body. Most BCCs appear on skin with a history of exposure to the sun such as the face, ears, scalp and upper trunk.

Squamous cell carcinoma (SCC): Approximately 16% of diagnosed skin cancers are SCC. This cancer begins in the squamous cells which are found in the upper layer of the epidermis. About 200,000 cases are diagnosed in the United States every year. SCC tends to develop in fair-skinned middle-aged and elderly people who have had long-term sun exposure. SCC can develop any place on the body including inside the mouth and the genitalia. SCC requires early treatment to prevent metastasis (spreading) to other parts of the body.

Melanoma: 4% of all diagnosed skin cancers are melanoma which begins in the melanocytes, cells within the epidermis that give skin its color. Melanoma has been called “the most lethal form of skin cancer” because it can rapidly spread to the lymph system and internal organs. In the United States alone, approximately one person dies from melanoma every hour. Older Caucasian men have the highest mortality rate. With early detection and proper treatment, the cure rate for melanoma is 95%

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.