Squamous cell carcinoma is the second most common cancer of the skin. More than 250,000 new squamous cell carcinomas are diagnosed every year in the United States. Middle-aged and elderly people, especially those with fair complexions are frequent sun exposure, are most likely to be affected. The cancer develops in the outer layer of the skin (the epithelium). Some squamous cell carcinomas arise from small sandpaper-like lesions called solar or actinic keratosis. It is possible for squamous cell carcinoma to spread to other areas of the body; therefore, early treatment is important.