Skin cancer is the most common form of cancer in the United States. More than two million people are diagnosed with skin cancer annually. According to the Skin Cancer Foundation (SCF), one in five Americans will develop skin cancer in the course of his or her lifetime. Each year, there are more new cases of skin cancer than breast, prostate, lung, and colon cancers combined. If left untreated, the disease can be deadly, but if skin cancer is caught while still in its early stages, the outlook is usually positive.