title: The molecular basis of nonmelanoma skin cancer: new understanding.
abstract: Nonmelanoma skin cancers, including basal cell carcinomas and squamous cell carcinomas, represent the most common malignant neoplasms in humans. Although many environmental and genetic factors contribute to the development of skin cancers, the most important is chronic exposure to UV radiation in sunlight. We now appreciate that the role of UV in the development of nonmelanoma skin cancers is 2-fold. First, UV radiation causes mutations in cellular DNA. Failure to repair these genetic alterations ultimately leads to unrestrained growth and tumor formation. Second, UV radiation has profound effects on the cutaneous immune system, inducing a state of relative immunosuppression that prevents tumor rejection. The purpose of this review is to educate clinical dermatologists about the recent developments in molecular biology and immunology that have greatly enhanced our understanding of how skin cancers arise. The clinical implications of this new knowledge are far-reaching and likely to soon impact the diagnosis, treatment, and prevention of a variety of benign and malignant skin conditions. It will be important for the clinician to understand the biological mechanisms underlying these new therapeutic developments to implement them effectively.
authors.affiliation: Department of Dermatology, Yale University School of Medicine, New Haven, Conn. 06520-8059, USA.
authors.forename: D
authors.initials: D
authors.lastname: Grossman
authors.forename: D J
authors.initials: DJ
authors.lastname: Leffell
mesh_terms: D002277:Carcinoma / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology / Q000517:prevention & control / Q000628:therapy; D002280:Basal Cell Carcinoma / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics; D004247:DNA / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair; D004781:Environmental Exposure; D006801:Humans; D007108:Immune Tolerance / Q000528:radiation effects; D008545:Melanoma; D008967:Molecular Biology; D009154:Mutation / Q000235:genetics; D012307:Risk Factors; D012867:Skin / Q000276:immunology / Q000528:radiation effects; D012878:Skin Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000276:immunology / Q000517:prevention & control / Q000628:therapy; D013472:Sunlight / Q000009:adverse effects; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: D004247:DNA