The historical aspects of photocarcinogenesis.

The concept of photocarcinogenesis is of fairly recent duration. Although cancer of the breast is described in the ancient Greek medical literature, skin cancer is not mentioned even as late as the 18th Century. This is most likely due to the poor survival of humans, 80% of people did not live past 40 years, and only 6% lived longer than 60 years. The first association of skin cancer (face and lip) with outdoor exposure dates to the middle of the 19th Century. About that time it was shown that it was Ultraviolet Radiation (UVR) that could cause skin and eye inflammation. It was not until the 20th Century that competent epidemiologic studies associated human skin cancer with chronic solar exposure, and it was shown that chemicals could augment the effects of UVR exposure. It has only been in the last quarter of a Century that it was found that UVR could cause immunologic changes that allow multiple skin cancers to develop. Advances in molecular biology have begun to show the cellular and molecular events that lead to UVR induced skin carcinogenesis.