Cancer is a disease of the body's cells.
Normally, the body's cells divide in an orderly way allowing your body to grow and to heal after an injury. Occasionally, however, some cells act in an abnormal way and may grow into a lump which is called a tumour. Benign tumours do not spread to other parts of the body. A malignant tumour is made up of cancer cells. These cells can spread beyond the area where the cancer first developed.