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Glioblastomas are the most common high grade (cancerous) primary brain tumour in adults. They can also occur, rarely, in children. Glioblastomas belong to a group of brain tumours known as gliomas, as they grow from a type of brain cell called a glial cell.

Glioblastoma is the more common name for a type of brain tumour called a grade 4 astrocytoma. They are fast growing and likely to spread. You may also hear them called glioblastoma multiforme, GBM or GBM4.

There are different types of glioblastoma:

  • Primary - This means the tumour first appeared as a grade 4 glioblastoma (GBM)
  • Secondary - This means the tumour developed from a lower grade astrocytoma

What causes glioblastomas?

As with most brain tumours, why glioblastomas begin to grow is not known. The Brain Tumour Charity is funding research into possible causes, focussed around our genes.

There is nothing you could have done, or avoided doing, that would have caused you to develop a brain tumour.

How are brain tumours formed?

Our genes control the way our cells grow and divide. Mutations (changes) in our genes can cause this process to go wrong, resulting in the cells growing uncontrollably and forming a tumour. These changes are often the result of a mistake being made when the cell copies its DNA before dividing.

Research, including that funded by The Brain Tumour Charity, is gradually discovering which genes are involved in which tumours.

This research is starting to be used (and may be able to be used more accurately in the future) to predict how people may respond to certain treatments and also the length of their overall survival (prognosis).

Learn more about how and why brain tumours form

Effectiveness of treatment

Unfortunately glioblastomas are aggressive tumours and often appear resistant to treatment. This is probably due to the fact that the cells within the tumour are not all of the same type. This is known as 'heterogeneity'. This means that treatments will kill off some types of cell within the glioblastoma, but leave others, which can then continue to grow.

However, some of the research into the genes, which play a role in glioblastoma (GBM) development and growth, are starting to give us information about who may respond better to certain treatments. For example biomarker tests, such as those documented in the factsheets below.

What's the prognosis?

Information about prognosis can be difficult to receive - some people do not want to know, whilst others do. There is no wrong or right answer as to whether or when to receive such information.

We've here to help you cope with a brain tumour diagnosis.

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