Reproduction of our body’s cells is normally strictly regulated:
cells only divide
when they are prompted to do so.
And cells that are no longer needed
die off and make space.
In cancer cells, these control mechanisms are compromised.
They reproduce in an uncontrolled manner
and form cancerous growths or tumors.
Cancer cells also acquire properties
that turn them into malignant cells.
These enable them to invade surrounding tissue and blood vessels
and form growths in other parts of the body known as “metastases”.
But what causes cancer?
All of the body’s cells have genetic material (a “blueprint”).
The parts of the blueprint that are implemented in a cell
determine its properties.
When a cell divides, it duplicates its genetic material
to pass on to the two daughter cells.
Errors can creep into the genetic material at this point.
Normally a number of errors need to coincide
to alter the properties of the cells to such an extent
that they become malignant.
• Most genetic errors occur randomly
and may accumulate in a single cell.
So the risk of cancer increases with age.
• Our lifestyle can increase the risk,
for example smoking,
UV radiation from the sun,
infection with certain viruses.
Being overweight and a lack of exercise
can make cancer more likely.
• Environmental factors may also cause errors in the genetic material,
such as radiation or particulate matter.
• However some genetic changes
which make cancer more likely
can also be inherited.
In short:
Cancers are caused by changes in genetic material.
These changes cause the body’s cells
to start dividing in an uncontrolled manner.
Malignant tumors,
which can invade surrounding tissue and blood vessels
and form metastases,
are referred to as cancer.