A brain tumour is a lump of cells, caused when cells in part of the brain divide and grow in an uncontrolled way.
If the tumour starts in the brain, it is known as a primary brain tumour. If the tumour started somewhere else in the body e.g. the lung, then spread to the brain, it is known as a secondary brain tumour or ‘metastases’.
There are over 130 different primary brain and spinal tumours, sometimes referred to as Central Nervous System (CNS) tumours. They are grouped and named according to:
- the type of cell they grow from
- where they are in the brain
- how it is likely to behave.
The way a tumour ‘behaves’ means how quickly it grows and how likely it is to spread.
Over 9,500 people are diagnosed with a primary brain tumour each year. This means that 27 people in the UK are diagnosed with a brain tumour every day. It is important to note that other conditions can cause similar signs or symptoms of brain tumours, but it is important to recognise these, so you can go to your doctor if you are concerned.
How are brain tumours graded?
Each year in the UK, approximately 4,300 people are diagnosed with low grade, slow growing brain tumours and 5,000 with high grade fast growing brain tumours. Combined, this represents less than 2 out of every 10,000 people in the UK.
Brain tumours are given a grade from 1 – 4 depending on how they are likely to behave.
Grade 1 and 2 tumours (low grade)
Grade 3 and 4 tumours (high grade)
Low grade brain tumours are:
- slow growing
- relatively contained with well-defined edges
- unlikely to spread to other parts of the brain
- have less chance returning (if they can be completely removed)
High grade brain tumours are:
- fast growing
- can be referred to as ‘malignant’ or ‘cancerous’ growths
- more likely to spread to other parts of the brain
- may come back, even if intensively treated