Cancer is a disease that originates in our own cells. A change in the DNA causes a special gene called an oncogene to be switched on. This leads to uncontrollable cell reproduction by mitosis. This is a cancer.
Cancer cells are able to replicate by overcoming the normal controls of cell division. They may form a lump or tumour which can cause damage to surrounding tissues and organs. Cancer cells may spread from the original (primary) tumour to form new (secondary) tumours throughout the body. When this happens the tumour is said to have metastasized.
This resource looks at how cancer cells develop, the causes of cancer and how treatments are used to tackle cancer.
There are a number of interactive features in this e-source: