Students should be able to describe cancer as the result of changes in cells that lead to uncontrolled growth and division.
Benign tumours are growths of abnormal cells which are contained in one area, usually within a membrane. They do not invade other parts of the body.
Malignant tumour cells are cancers. They invade neighbouring tissues and spread to different parts of the body in the blood where they form secondary tumours.
Scientists have identified lifestyle risk factors for various types of cancer. There are also genetic risk factors for some cancers.