Causes of cancer

Resource for Causes of cancer and fun search portal . Continue for our current list for the Causes of cancer

Love Poems, Love Calculator

Arts And Entertainment

Health And Fitness

Home Based Business

Self Improvement

Dating, Love, Sexuality

Relationships

Funny Pictures

MSN Nick Names,Display Pictures,Emoticons,Background

Cancer is, ultimately, a disease of genes. Typically, a series of several mutations is required before a cell becomes a cancer cell. We distinguish between oncogenes, which promote cancer when "switched on" by a mutation, and tumor suppressor genes, which prevent cancer unless "switched off" by a mutation. These mutations can have various causes: radiation or chemicals called carcinogens; some inherited predisposition is not uncommon; some viruses that can cause cancer have also been described. Usually, they carry in their genome some oncogene or tumor suppressor inactivating gene. In about 15% of all cancers, viruses seem to play a role; Bacteria, like Helicobacter pylori, also induce carcinogenesis by a process of chronic inflammation. Finally, damage by free radicals, which are a natural by-product of oxygen metabolism, can cause mutations in the DNA.

In cellular model systems, cells are exposed to carcinogenic influences (chemicals, radiation). In these systems, the first signs of a cell developing into a tumor cell are:

  • Immortality. The usual number of cell divisions for a mammalian cell is 50-60 (cell senescence), then it ceases to divide. Tumor cells keep dividing forever.
  • Altered morphology.
  • Building of cellular clusters (Foci).
  • Loss of contact inhibition.
  • Low or no need for growth factors.

Items 2-4 (above) can sometimes be traced to mutations in genes that result in a disruption of cell adhesion. Some cell adhesion proteins are oncogenes.

In medicine, cancer is a general term for any of a number of different diseases where some of the body's own cells divide in an uncontrolled manner. The resulting new cells can form a malignant tumor (a neoplasm) or propagate throughout the body.

  • Rare Adult & Pediatric Cancers
    Provides information, support, forums, links and news.
  • MyOwnBiopsy
    Provides "translations" of cancer pathology reports from medical jargon into understandable lay terms.
  • Cancer Monthly
    Presents information on research results.
  • Cancer.com
    Provides treatment information, support group listings, online education, decision-making resources, physician locator services and risk assessment tools.
  • EMedicine Health: Cancer Symptoms
    Consumer health resource center providing information on common symptoms.