What is Cancer?
When we have a group of cells growing out of control, they form a tumour. A tumour is simply a lump of abnormal cells which are multiplying when they shouldn’t. Cancer is the presence of a tumour.
Tumours can cause a number of problems:
• They can spread to normal body tissues nearby.
• They can spread to other parts of the body through the blood and lymphatic systems.
• They can put physical pressure on other body structures.
As there are about two hundred types of cells in our bodies, there are about two hundred different types of cancer.
Left untreated, tumours which spread have the potential to cause death.
A normal human body contains many trillions of cells – estimates vary between about ten and a hundred trillion. Considering that we all started out as a single cell, that is amazing.
Cells multiply by dividing in two to double their number. By the time we are born, we are made of somewhere in the region of a trillion cells – all formed from one cell in the nine months between conception and birth. We continue to grow and our cells continue to divide up to about 18 years of age; then they stop. If they didn’t, we would continue to grow throughout adulthood and we would all be giants. Our genes contain a mechanism to prevent further cell division and stop us growing indefinitely.
In cancer, something has happened to disable this mechanism, so the affected cell grows and divides out of control. This is how tumours form. Because the cells of the tumour are our own body cells, they are not seen as invaders by our immune systems and so are allowed to proliferate, unchecked.
Factors which can cause a cell to reproduce in this manner include “carcinogenic” chemicals such as asbestos, some of the constituents of cigarette smoke and benzene. Other factors include some viruses (eg HPV, responsible for many cervical cancers) and exposure to radioactivity. Sometimes, the changes happen spontaneously with age. One person in every three will have some form of cancer at some stage of their life.
Most survive it.
(c) Caroline Turner BSc (Hon)
If you want to read our new flyer which explains in simple terms about Prostate Cancer, its treatment and their after effects, or you want to speak to someone locally, who has been through it, then please download our “Below The Belt” leaflet here.