Contains the full lesson along with a supporting toolkit, including teachers’ notes.
What is Cancer?
One in three of us will get cancer in the course of our lives. About half of all cancers are thought to be caused by factors associated with diet and lifestyle and can be avoided by following the Code Against Cancer. Enormous advances have been made in the treatment of cancers and many of them can be cured if diagnosed early and so it makes sense for us to become better informed.
The process of growth and division of cells (the cell cycle) has two main stages – interphase, when the cell grows andchromosomes are replicated, and mitosis when the nucleus and then the whole cell divides. These stages can be subdivided into a number of phases, as seen above, that are regulated bycontrol genes and growth factors.
Cancer occurs when mutation occurs in a cell cycle control gene or a gene producing growth factors or receptors so that they become overactive; they are then called oncogenes, or cancer causing genes. Normal cell cycle control is then lost.
The cancerous cell divides in an uncontrolled way, passing on itsoncogenes and forming a cluster of similar cells called atumour. If the cells remain together, it is called a benign tumourbut if the cells break away and are transported in the blood or lymphatic system to invade and cause cancers in other tissues, it is a malignant tumour.