Grading brain tumours

Grading a brain tumour can help your doctor understand how quickly it might grow and help plan treatment.

What is grading?

The grade of a brain tumour describes how abnormal the cells look under a microscope. Your doctor will use the information about the grade along with results of molecular markers (biomarkers). This can help them to understand how quickly a brain tumour may grow, and how best to treat it.

Brain tumours can be:

  • Low-grade tumours

    Low-grade tumours usually grow slowly and may not cause symptoms for a long time. They are very unlikely to spread outside of the brain. But they may cause problems as they grow and press on or invade nearby areas of the brain. This can cause symptoms such as seizures (fits). Other symptoms depend on which part of the brain is affected by the tumour.

    Sometimes a low-grade brain tumour can change over time and become high-grade.

  • High-grade tumours

    High-grade tumours grow faster than low-grade tumours. They cause problems by spreading into and damaging nearby areas of the brain. Rarely, they may spread to other parts of the brain or the spinal cord. It is very rare for brain tumours to spread to other parts of the body.

Sometimes brain tumours behave differently to what is usually expected for the grade. This may happen if the tumour has certain genetic changes called molecular markers (biomarkers). For example, some brain tumours that may look low-grade can have certain genetic changes that mean they behave more like high-grade tumours.

Grade 1

These tumours are low-grade and grow slowly. They are sometimes called benign tumours because they are unlikely to come back after treatment.

Grade 2

These tumours are also low-grade and usually grow slowly. Depending on the type of brain tumour, they may be more likely to:

  • come back after treatment
  • change over time and become high-grade or malignant (cancerous).

Your doctor can explain more.

Grades 3 and 4

These tumours are high-grade (malignant) and grow more quickly.

Getting support

We understand that waiting to know the stage and grade of your cancer can be a worrying time. We are here if you need someone to talk to. You can:

About our information

This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.

Professor Catherine McBain, Consultant Clinical Oncologist & Honorary Professor in Cancer Sciences

Professor Catherine McBain

Reviewer

Consultant Clinical Oncologist

Date reviewed

Reviewed: 01 May 2024
|
Next review: 01 May 2027
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