Brain tumours - everything you need to know
16th January 2023
Brain tumours can be complicated to understand. Some brain tumours grow slowly, and may not even be classed as cancer, while others can grow fast, and be hard to treat. Unfortunately, some types of brain tumour still have no cure. But this situation is changing, and thanks to research-led improvements in diagnosis and treatment, survival is steadily improving. So what exactly is a brain tumour? How do they begin, and what treatments exist? Most importantly, how is research helping to improve life for people with brain tumours?
What is a brain tumour?
A brain tumour is a growth or ‘lump’ that develops in or around the brain or spinal cord (the central nervous system). Tumours start when healthy cells become changed in a way that causes them to grow and divide out of control- usually because of DNA damage. The damage causes tumour cells to look and behave very differently to healthy cells.
Brain tumours can sometimes be called ‘benign’, which means they are non-cancerous, or ‘malignant’, which can mean they are cancerous:
- Benign brain tumours: grow very slowly. They are usually easier to treat and less likely to spread or come back after treatment.
- Malignant brain tumours: can grow quickly. They are more likely to spread in the brain and return following treatment.
What do brain tumour ‘grades’ mean?
Doctors also sometimes group brain tumours into one of four different ‘grades’, depending on how altered the tumour cells look under a microscope. The higher the grade, the more the cells have changed, and the more malignant the brain tumour might be.
Benign tumours are usually Grade 1 or 2, or ‘low-grade’ tumours. Malignant tumours are generally Grade 3 or Grade 4, or ‘high-grade’ tumours.
But tumours do not always fit into one single type or grade. Some tumours might be a mix of benign and malignant, or low-grade and high-grade for example. Or they might progress from low grade to high grade over time.
What causes brain tumours?
Researchers still don’t know all the steps that can cause brain tumours to develop, though they do know that complex combinations of factors are probably involved. Most brain tumours cannot be prevented.
Exposure to some types of radiation is known to cause a small number of brain tumours. Some inherited genetic conditions can also increase a person’s risk of developing specific types of tumours.
Like many cancers, older age is also a recognised risk factor for brain tumours, meaning we are more likely to develop a brain tumour as we age. But brain tumours can and do affect anyone of any age. In fact, they are the biggest cancer killer of adults and children under 40 in the UK.
What types of brain tumour are there?
More than 130 different types of brain tumour exist. They can start anywhere in or around the brain, including:
- the spinal cord
- nerves close to the brain and spinal cord
- the pituitary and pineal glands
- the outer layers of membrane that cover the spinal cord and brain (meninges)
Meningioma starts in the meninges. It is the most common form of primary brain tumour, meaning the tumour started in the brain and not elsewhere in the body. Most meningiomas are considered low-grade and benign (i.e., not cancerous), though some may come back after treatment.
Gliomas are a form of brain tumour that grow from glial cells in the brain. There are several different types of glioma, and a type called astrocytoma is the most common.
Astrocytomas can be low-grade or high-grade. Glioblastoma multiforme is a Grade 4 astrocytoma. These are one of the most deadly types of primary malignant brain tumour. Much brain cancer research focuses on finding new ways to treat glioblastoma. For example, Worldwide Cancer Research-supported scientists in France are trying to understand how targeting a certain gene in glioblastoma cells may help to reduce their growth and improve treatment effectiveness.
Medulloblastomas begin in the cerebellum, at the bottom of the skull. Medulloblastomas are the most common malignant tumours in children, though they are still relatively rare in both children and adults.
What are the symptoms of a brain tumour?
As brain tumours grow, they can press on the surrounding area and affect how the brain works. Often the first sign of a brain tumour might be a bad headache that is worse in the morning (the sort which wakes you up from sleep).
Other symptoms can also include:
- Vision or hearing changes
- Progressive changes in movement or balance
- Tingling or numbness
- Problems with swallowing or speech
- Mood or personality changes, memory problems
Of course, these symptoms can also be caused by many other more common conditions too. It’s always worth checking with your doctor if you have any worries.
How is brain cancer treated?
Treatment for brain cancer can depend on the size, type, and location of tumour. It also matters whether the tumour is primary or secondary (that is, if it started in the brain or somewhere else in the body).
Very low-grade tumours can sometimes be treated with surgery alone. Higher-grade tumours require a mix of surgery, and chemotherapy and/or radiotherapy.
Sometimes surgery is not an option as the risk of damage to surrounding areas is too high, or only part of the tumour can safely be removed. If this is the case, then more specialised forms of targeted radiotherapy might be used.
Carmustine implants are also a new type of specialised chemotherapy treatment that can sometimes be used to treat glioblastoma multiforme in adults. With this form of chemotherapy, a dissolvable implant which contains the anticancer drug is placed onto the tumour during surgery.
Doctors might also try other forms of treatment if the cancer has spread to the brain from elsewhere in the body. These might include targeted therapies, which exploit specific faults in the tumour cells to kill them, or immunotherapies, which help our immune system more effectively target the tumour. Use of these treatments very much depends on the type and location of the original (‘primary’) cancer.
How is research helping people with brain cancer?
Thanks to research, survival for people with malignant brain tumours is improving. Now, 3 in 20 people with brain cancer will live for at least 10 years, compared to just 1 in 20 in the 1970s. But this number is still shockingly low compared to some other cancers.
We know that more research will help ensure that survival rates keep getting better. You have already helped Worldwide Cancer Research give £4.7million to vital brain tumour research projects. Here’s how the generosity of our Curestarters is helping to kick-start new cures, and give new hope to people with brain cancer.
In 2021, scientists supported by a collaboration between Worldwide Cancer Research and The Brain Tumour Charity managed to pin down how a specific genetic change, called H3K27M, can lead to a rare form of childhood tumour called diffuse midline glioma. This important work can now form the basis of urgent research to find the most effective way of targeting and treating the condition- which still has no cure.
And in 2022, Worldwide Cancer Research scientists in Spain made a breakthrough in understanding how brain cancer cells can become resistant to radiotherapy treatment. The researchers hope this new understanding will help to make radiotherapy treatments more personalised, and more effective.