Molecular mechanisms of carcinogenesis

In 1775, the London surgeon Sir Percival Pott reported a link between scrotal skin cancer in adult men and their chronic exposure in boyhood, as chimney sweeps, to soot. The significance of this first recognition of the latent nature of cancer was not realized, however, until 1950, when occupational exposure of workers to aromatic amines in the dyestuff, textile, and rubber industries was shown to be clearly associated with an increased risk of urinary bladder cancer later in life (Gorrod and Manson, 1986). Likewise, positive associations between cigarette smoking and lung cancer (Hoffmann and Hecht, 1990), and exposure to asbestos and lung cancer and mesotheliomas (Mossman and Gee, 1989) were established. Since the latent period between initial exposure to a carcinogen(s) and clinical manifestation of cancer may take 15 to 25 and in some cases up to 40 years, elucidation of biochemical and molecular changes involved in cancer development has been particularly difficult. Although substantial progress toward understanding the complex process of carcinogenesis has been made during the past 50 years, its intricate mystery is not yet fully unraveled.