The skin is the largest organ of the body. An average adult has a skin surface area of between 16 and 22 square feet, most of which is between 2–3 mm (0.10 inch) thick. The average square inch of skin holds 650 sweat glands, 20 blood vessels, 60,000 pigment cells (melanocytes), and more than 1,000 nerve endings. As the outer covering of the body, the skin protects and insulates the underlying tissues and organs, regulates the body’s temperature, synthesizes vitamin D, stores water and fat, and senses the outside environment.
The incidence of skin cancer in people under age 40 is increasing dramatically in the United States, particularly among women.1 One in five Americans will develop skin cancer in his or her lifetime.
While melanoma is widely-recognized as a serious and potentially lethal form of skin cancer, non-melanoma skin cancers are much more common, and can be equally serious. Basal cell carcinoma (BCC) accounts for between 80-90% of all non-melanoma skin cancers diagnosed, while a more serious type called squamous cell carcinoma (SCC) accounts for 10-20%.
Risk factors for skin cancer include a personal history of the disease, a family history of skin cancer, having numerous moles or atypical moles, fair skin, having had at least one severe sunburn as a child, and having a weakened immune system. Sun exposure is the most common cause of skin cancer. Protection against the sun is therefore the best way to prevent skin.