Skin cancer is the most common type of cancer in the United States.
An estimated 40 to 50 percent of Americans who live to age 65 will have skin cancer at least once. Basal cell carcinoma accounts for more than 90 percent of all skin cancers in the United States. It is a slow-growing cancer that seldom spreads to other parts of the body. Squamous cell carcinoma also rarely spreads, but it does so more often than basal cell carcinoma. Squamous cells are flat and make up most of the epidermis, the outer layer of the skin.