40% of all cancers spread to the brain
What is an astrocytoma brain tumour?
Astrocytomas are the most common type of primary glioma brain tumour in both children and adults.
An astrocytoma brain tumour develops from brain cells called astrocytes. When astrocytes form an astrocytoma brain tumour, damage can be seen in the DNA and they no longer undergo apoptosis (the cells don’t die when they are supposed to). When this process fails in astrocytes, the cells continue to grow in an uncontrolled way and form into a brain tumour.
Astrocytoma tumours do not spread to other parts of the body because astrocyte cells are only found in the brain and spinal cord.
The prognosis for astrocytoma varies between grades and will vary between individuals.
What is an astrocyte cell?
Astrocytes are a type of glial cell, which is the collective name for cells that form a web of connective glial tissue to support the neurons (nerve cells) within the brain and spinal cord. These cells are named after their three-dimensional shape – “astro”, meaning star, and “cyte” meaning cell.
Other types of glial cells are oligodendrocytes and ependymal cells. Astrocytoma, oligodendroglioma and ependymoma brain tumours are therefore all classified as glioma tumours because they develop from glial cells, and in some cases a “mixed glioma” brain tumour may contain a mixture of these different cells.
- Astrocytes help to maintain the balance of water and key nutrients that support the function of neurons
- They contribute to maintenance of the blood brain barrier, which protects the brain from toxins
- Astrocyte cells are able to regulate blood flow, and hence oxygen and nutrients carried in the blood, to maintain the health of neurons
- Astrocytes provide energy to support memory
- Astrocytes also help the brain to process information
Classification of astrocytomas
Astrocytomas are divided into the following classifications by the World Health Organisation (WHO):
Astrocytoma grade 1: low-grade astrocytoma
Grade 1 astrocytomas are usually found only in children and teenagers. They are the most slow-growing (low-grade) form of astrocytoma and carry the longest prognosis. The most common type of grade 1 astrocytoma is pilocytic astrocytoma, also known as juvenile pilocytic astrocytoma (JPA)
Astrocytoma grade 2: diffuse astroctyoma
Grade 2 astrocytomas can occur in children, teenagers and adults, but is more common in adults. They are initially a slow-growing (low-grade) form of brain tumour but have a tendency to progress to a higher grade over time, usually over a number of years.
Grade 2 astrocytomas are also referred to as diffuse astrocytomas because of the way they infiltrate into healthy brain tissue. This is due to the nature of astrocytoma cells, which reach between and around the neurons. The prognosis of low-grade 1 and 2 astrocytomas will vary between individuals.
Astrocytoma grade 3: anaplastic astrocytoma
Grade 3 astrocytoma, also known as anaplastic astrocytoma, is a malignant form of brain cancer. It often spreads to other parts of the brain.
The prognosis for higher-grade 3 and 4 brain tumours will be worse than those classified as grade 1 or 2 but will of course still vary between individuals.
Astrocytoma grade 4: glioblastoma multiforme (GBM)
Astrocytoma and glioblastoma multiforme (GBM) are basically the same kind of tumour because a GBM may well have developed from a lower grade of astrocytoma, but the name changes once it is classified as grade 4. This is to reflect the fact that a grade 4 astrocytoma usually has other cancerous cells within it, such as oligodendrocytes for example. Read more about glioblastoma multiforme (GBM) tumours.
How is an astrocytoma brain tumour treated?
The first line treatment for an astrocytoma in adults is usually surgery, if the tumour occurs in a position that makes this possible. Surgery is usually followed by radiotherapy.
For astrocytoma in children, chemotherapy may be the first line of treatment offered.
For astroctyomas that are classified grade 3 or 4, chemotherapy will be offered alongside radiotherapy. This is more unusual for slow-growing low-grade astrocytomas because current chemotherapy drugs, such as Temozolomide , are only effective against cells that are dividing quickly.
What causes an astrocytoma?
The exact causes of an astrocytoma are not yet clear. We have some information about causes and risk factors that may contribute to the development of brain tumours here.
How can we find a cure for astrocytomas?
Research we are funding across all of our Centres of Excellence will help lead towards finding a cure for astrocytoma brain tumours.
Our team at the University of Plymouth Low-Grade Brain Tumour Centre of Excellence are researching a range of mutations in brain tumour cells that initiate tumour progression and drive growth, transforming slow-growing low-grade gliomas into high-grade gliomas. Their discoveries are designed to enable new treatments to be developed and tested to halt and hopefully reverse this process.
Pioneering research at our Brain Tumour Research Centre of Excellence at Queen Mary University of London is focused on using GBM stem cells to help develop unique, patient-specific treatments that should also benefit those with lower grades of astrocytoma brain tumours.
The team of research and clinical experts at our Centre of Excellence at Imperial College, London, are part of a global collaboration looking at how the ketogenic diet can influence gliblastoma (GBM or astrocytoma grade 4) metabolism and help in the effective treatment and management of living with this brain tumour. They are also studying the influence of arginine deprivation on GBM cells and are working towards a clinical trial to investigate this further. They expect that their discoveries will also benefit low-grade astrocytoma.
We also fund BRAIN UK at Southampton University, the country’s only national tissue bank registry providing crucial access to brain tumour samples for researchers from all clinical neuroscience centres in the UK, effectively covering about 90% of the UK population, and an essential component in the fight to find a cure for all grades of astrocytoma.