Cancer facts: how do we get cancer?
Genes in our cells contain instructions that control the way cells behave. If certain genes are damaged or changed, they can affect the way our cells grow and develop. Cancer is the disease caused by abnormal cells multiplying out of control.
Some genetic changes leading to cancer are caused by behaviors such as smoking, eating an unbalanced diet, or drinking too much alcohol. Other causes include factors in our environment, such as toxic chemicals, and viruses. Many causes of cancer are still unknown.
Inherited genes may also increase the risk of developing certain types of cancer. For example, some women inherit a gene that makes them more likely to develop breast cancer.
Cancer facts: cancer and the immune system
The body has its own natural way of defending itself, called the immune system. This protects us from things that are “foreign” to the body, such as bacteria or viruses. It can also protect against abnormalities arising in our own bodies. When our cells change and start multiplying in an uncontrolled way, our immune system can intervene and eliminate those abnormal cells. When abnormal cells manage to escape from our immune system’s checking process, the result can be cancer.
