In English | En español
Questions About Cancer? 1-800-4-CANCER

Understanding Cancer Series

< Back to Main
  • Posted: 01/28/2005
  • Reviewed: 09/30/2009

Page Options

  • Print This Page
  • Print This Document
  • View Entire Document
  • Email This Document
  • View/Print PDF
  • View/Print PowerPoint

Slide 24

:

What Causes Cancer?

< Previous SectionNext Section >

Cancer is often perceived as a disease that strikes for no apparent reason. While scientists don't yet know all the reasons, many of the causes of cancer have already been identified. Besides intrinsic factors such as heredity, diet, and hormones, scientific studies point to key extrinsic factors that contribute to the cancer's development: chemicals (e.g., smoking), radiation, and viruses or bacteria.

What Causes Cancer?