Cancer' is therefore a generic term used to describe a group of at least a hundred diseases that occur when malignant forms of abnormal cell growth develop in one or more body organs. Cancer arises after a series of genetic mutations remove the normal checks on cell growth. These cancer cells continue to divide and grow to produce tumours. Cancer cells can invade adjacent structures and spread via the lymph or blood to distant organs. Some of the
biological mechanisms that change a normal cell into a cancer cell are known while others are not yet known.