• James Norris
  • Deanne King


Carcinogenesis describes the process that transforms a normal cell into a malignant cell. Knudsen studied the inheritance of retinoblastoma and theorized that carcinogenesis is a multistep process [1]. He proposed the idea that two mutations are necessary for the development of retinoblastoma. Some individuals have an inherited predisposition to retinoblastoma, resulting in bilateral presentation at an early age. In this multifocal form, only one exogenous mutation is required, because the first mutation is inherited (Fig. 8-1A). In the sporadic form, the disease is unifocal and characterized by later onset (Fig. 8-1B). In this case, “two hits” must occur in the same cell—a much rarer event.


Endometrial Cancer Thymine Dimer Nitro Amine Thorium Oxide Promoter Phorbol Ester 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Knudsen AG Jr: Mutation and cancer: statistical study of retinoblastoma. Proc Natl Acad Sci USA 1971, 68: 820–823.CrossRefGoogle Scholar
  2. 2.
    Fearon ER, Vogelstein B: A genetic model for colorectal tumorigenesis. Cell 1990, 61: 759–767.PubMedCrossRefGoogle Scholar
  3. 3.
    Pitot HC: The molecular biology of carcinogenesis. Cancer 1993, 72 (Suppl 3): 962–970.PubMedCrossRefGoogle Scholar
  4. 4.
    Couch DB: Carcinogenesis: basic principles. Drug Chem Toxicol 1996, 19: 133–148.PubMedCrossRefGoogle Scholar
  5. 5.
    Weisburger JH, Horn CL: The causes of cancer. In Textbook of Clinical Oncology. Edited by Holleb AI, Fink DJ, Murphy GP. Atlanta: American Cancer Society, Inc; 1991: 80–98.Google Scholar
  6. 6.
    Key TJ, Beral V: Sex hormones and cancer. International Agency for Research on Cancer Scientific Publications 1992, 116: 255–269.Google Scholar

Copyright information

© Current Medicine, Inc. 2000

Authors and Affiliations

  • James Norris
  • Deanne King

There are no affiliations available

Personalised recommendations