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How brain tumours are graded

Brain tumours are graded 1-4 according to their behaviour, such as the speed at which they are growing, and how likely they are to spread into other areas of the brain. Over time, some brain tumour's behaviour can change and the tumour may become, or come back as, a higher grade tumour.

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 graded from 1 – 4 depending on how they are likely to behave.

Confirming the diagnosis of the different grades of brain tumours is done, where possible, by analysing cells from the tumour, taken during a biopsy or during surgery. A neuropathologist examines the cells in the laboratory, looking for particular cell patterns that are characteristic of the different types and grade of brain tumour.

Actions to take

Questions to ask a doctor

Resources to explore

Actions to take

  • If you are not sure what your grading means, then make sure you talk to your doctor or clinical nurse specialist. Don't be afraid to get in touch with them with these types of questions - they are there to support you!
  • You might want to consider asking for a second opinion about your tumour diagnosis. You should talk to your GP or consultant about this. In our experience dealing, healthcare professionals are very open to allowing second opinions, recognising the sensitive nature of the diagnosis.
  • Talk through the types of symptoms that you might experience, and how this might affect your day to day life. For example, driving or employment.

Questions to ask a doctor

  • What are the recommended treatment options for my grade and type of tumour?
  • Does my tumour grade and type mean I have cancer?
  • Are there clinical trials for this grade of tumour that I could be suitable for?

Resources to explore

Why is the grade important?

Accurate diagnosis is important as it allows your medical team to give you information about how the tumour could behave in the future, and also to recommend treatment options. This could include a clinical trial.

Sometimes confirming the grade can be difficult as some low grade and high grade tumours can look very similar.

Low grade tumours

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).

Grade 1 and 2 tumours are low grade, slow growing, relatively contained and unlikely to spread to other parts of the brain. There is also less chance of them returning if they can be completely removed. They are sometimes still referred to as 'benign brain tumours'.

The term 'benign' is less used nowadays as this can be misleading. These low grade brain tumours can still be serious.

This is because a 'benign' brain tumour can cause harm by pressing on and damaging nearby areas of the brain, due to the limited space capacity of the skull. They can also block the flow of the cerebrospinal fluid (CSF) that nourishes and protects the brain, causing a build-up of pressure on the brain.

High grade tumours

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.

Grade 3 and 4 tumours are high grade, fast growing and can be referred to as 'malignant' or 'cancerous' growths.

They are more likely to spread to other parts of the brain (and, rarely, the spinal cord) and may come back, even if intensively treated. They cannot usually be treated by surgery alone, but often require other treatments, such as radiotherapy and/or chemotherapy.

'Mixed grade' tumours

Some tumours contain a mixture of cells with different grades. The tumour is graded according to the highest grade of cell it contains, even if the majority of it is low grade.

Get support

If you need someone to talk to or advice on where to get help, our Support and Information team is available by phone, email or live-chat.

Share your experiences and help create change

By taking part in our Improving Brain Tumour Care surveys and sharing your experiences, you can help us improve treatment and care for everyone affected by a brain tumour.

If you have further questions, need to clarify any of the information on this page, or want to find out more about research and clinical trials, please contact our team:

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