how and why is cancer so deadly

Question: how and why is cancer so deadly
- Keywords:
  cancer,
  deadly
Asked by megan douglas to Hummy, Lewis, James, Sandra on 13 Mar 2017.
- Lewis Wright answered on 13 Mar 2017:
  
  Cancer is your own mutated cells, so whereas normally if you have a bacterial or viral infection, your body recognises that it isn’t from you, and sets about removing it.
  
  Your immune system cannot tell the difference between healthy and cancerous cells, so it goes basically undetected until a doctor finds it.