The scientific basis of skin cancer.
Mutations in tumor suppressor gene p53 are very common in many human cancers. They are present in more than 90% of squamous cell carcinomas (SCCs) and are usually found in actinic keratoses (AKs). Data demonstrate a strong relationship between the early effects of ultraviolet radiation (UVR) on p53 in skin and the development of AK and SCC. The purpose of this article is to review specific data about the p53 tumor suppressor gene, UVR, and their interaction to cause AKs. The published, peer-reviewed literature is reviewed and a published proposal for the mechanism for UVR-induced carcinogenesis is explained. The specific effect of UVR on the p53 tumor suppressor gene, including its impact on apoptosis, in humans, and in animals, suggests a cause-effect relationship between UVR and the earliest mutations seen in AKs. AKs result from UVR in a process by which UVR mutates a known tumor suppressor gene (p53). It is likely that the mutated cells expand preferentially in a clonal fashion at the expense of the normal surrounding keratinocytes to develop into a clinical lesion of AK.