ABSTRACT
Epidemiology is mainly concerned with measuring disease frequency in a given population and with the evaluation of variations with disease frequency in different populations and/or according to the presence of specific factors, which may represent causal factors for the disease. In addition, epidemiology describes how a given disease progresses once it has been developed and assesses those factors, which may affect the outcome of a disease. A fundamental study to provide a reliable picture of the descriptive epidemiology of non-melanoma skin cancer was the one conducted by Scotto et al. in several areas in the United States, in two separate periods, that is, 1971–1972 and 1977–1978. Particular attention has been paid to the epidemiology of nonmelanoma skin cancer in Australia, where the highest ever incidence rates have been documented. Skin cancers originating on the ear were responsible for more than a quarter of all deaths caused by nongenital lesions.
