Squamous-cell carcinoma (SCC), also known as epidermoid carcinoma, comprises a number of different types of cancer that begin in squamous cells. These cells form on the surface of the skin, on the lining of hollow organs in the body, and on the lining of the respiratory and digestive tracts. The squamous-cell carcinomas of different body sites can show differences in their presented symptoms, natural history, prognosis, and response to treatment. .