• Question: When abnormal cells are produced by the body to cause cancer, why do they divide faster than normal cells and why can't the body fight against them that well?

    Asked by alexsarah to Jo, Leo on 24 Jun 2010 in Categories: .
    • Photo: Leo Garcia

      Leo Garcia answered on 24 Jun 2010:

      That is a great question, which is at the heart of cancer research – just what happens inside the body that stops the body from fighting off cancer.

      Firstly, the body doesn’t ‘produce’ abnormal cells. It only takes one cell to have damaged DNA which causes a cancerous mutation for cancer to occur – and this damage could occur through any number of ways, such as radiation exposure.

      Cancer cells do not necessarily divide faster than normal cells – instead, there are just more cells surviving than are dying, so you have a net gain of cells.

      The body does attempt to fight off cancerous cells:


      And there are genes within the body which create molecules to prevent the growth of tumours:


      However, when these genes are not present, tumours can grow in an unregulated way. The immune system does attempt to fight off cancer:


      But having cancer weakens the immune system, and the immune system response just isn’t enough to kill of all the cancer cells. That’s why people need treatment from doctors to help their bodies win the fight against those cancerous cells.