Cancer is caused mainly due to changes in the DNA. The DNA inside the cell contains instructions for the cell on how to grow and divide. If errors are found in the instructions then the cell might become cancerous.

What do gene mutations do?
A gene mutation can instruct a healthy cell to:

  • Allow Rapid Growth: A gene mutation makes the cell to grow and divide more rapidly.
  • Fails to stop Uncontrolled Cell Growth: The normal cells contain genes called the tumor suppressor genes that recognize these uncontrolled cell growths and act to stop it. However, if a mutation occurs in a tumor suppressor gene, that gene may become less effective or may be turned off completely. This allows a mutated cell to continue growing and dividing.
  • Mistakes while repairing DNA errors. DNA repair genes identify and correct DNA mutations. A mutation in a DNA repair gene means that the gene may miss some DNA errors. This allows more DNA mutations to occur and may lead to cancer.

These mutations are the most common ones found in cancer. But many other gene mutations can contribute to causing cancer.

What causes gene mutations?
Sometimes you’re born with a genetic mutation. Or a genetic mutation can be caused by forces within your body, such as hormones, viruses and chronic inflammation. Genetic mutations can also be caused by forces outside of your body, such as ultraviolet (UV) light from the sun, cancer-causing chemicals (carcinogens) or radiation.