What is a tumour?
A tumour is an abnormal growth of cells. Cells are the body's basic building blocks – they make up tissues and organs. The body constantly makes new cells to help us grow, replace worn-out tissue and heal injuries.
Normally, cells multiply and die in an orderly way, so that each new cell replaces one lost. Sometimes, however, cells become abnormal and keep growing. In solid cancers, such as brain cancer, the abnormal cells form a mass or lump called a tumour. In some cancers, such as leukaemia, the abnormal cells build up in the blood.
Benign and malignant tumours
Tumours are often classified as benign (not cancer, slow-growing and unlikely to spread) or malignant (cancer, faster-growing with the potential to spread). These terms are useful for tumours in other parts of the body. With brain tumours, however, the difference is not as clear.
A slow-growing brain tumour that is unlikely to spread could be called benign. Other slow-growing brain tumours are called low-grade. These grow slowly but can spread through the brain. Benign tumours in certain areas of the brain can still be life-threatening and may require urgent treatment.
Malignant (cancerous) tumours are life-threatening and can grow rapidly. They may spread within the brain and spinal cord, or come back soon after treatment. However, some malignant tumours respond well to treatment.
Primary and secondary cancer
A brain tumour may be a primary or secondary cancer. Cancer that first develops in the brain is called primary brain cancer. It rarely spreads to other parts of the body, but may spread to other parts of the brain.
Sometimes cancer starts in another part of the body and then travels through the bloodstream to the brain. This is known as a secondary cancer or metastasis. A metastasis keeps the name of the original cancer. For example, bowel cancer that has spread to the brain is still called metastatic bowel cancer, even though the person may be having symptoms caused by how the cancer is affecting the brain.
The brain and spinal cord
The brain and spinal cord make up the central nervous system (CNS). Together, the different parts of the CNS control the activities of the mind and body.
The brain interprets information received via the nerves from the senses (taste, smell, touch, hearing and sight). It also sends messages via the nerves to the muscles and organs. The main parts of the brain are the cerebrum, the cerebellum and the brain stem.
The spinal cord extends from the brain stem to the lower back. It is made up of nerve cells and nerve bundles that connect the brain to all parts of the body through a network of nerves called the peripheral nervous system. The spinal cord lies in the spinal canal, protected by a series of bony vertebrae called the spinal column.
Both the brain and spinal cord are surrounded by thin layers of protective tissue (membranes) called the meninges.
Inside the skull and vertebrae, the brain and spinal cord float in a liquid known as cerebrospinal fluid (CSF). The fluid-filled spaces inside the brain are called ventricles.
At the base of the brain is the pituitary gland, which is about the size of a pea. The pituitary gland releases chemical messengers (hormones) into the blood. These hormones control many body functions, including growth and development, and also tell other glands to start or stop releasing hormones.
The brain and spinal cord are made up of two main types of cells: neurons and glial cells. Neurons process and send information. Glial cells support the neurons by holding them in place, supplying nutrients and clearing away dead neurons, waste products and germs.
The role of the brain
The brain is the most complex organ in the human body and is often called the body's command centre. It controls things you do voluntarily, such as speaking or making decisions, as well as those you do automatically, such as blood circulation and heart rate.
The largest part of the brain is the cerebrum, also known as the cerebral cortex. This is made up of different parts.
The cerebral hemispheres
The cerebrum is divided into two halves called hemispheres. The right hemisphere controls muscles on the left side of the body, and the left hemisphere controls muscles on the right side as well as speech.
The two hemispheres are connected by a band of nerve fibres called the corpus callosum (see diagram above), which transfers information between them.
Lobes of the brain
Each hemisphere is divided into four main areas. These are called the frontal, parietal, occipital and temporal lobes. Each lobe controls different functions, as shown in the diagram below.
What is a brain or spinal cord tumour?
A brain or spinal cord tumour occurs when abnormal cells grow and form a mass or a lump. The tumour may be called benign (not cancerous) or malignant (cancerous), but both types can be serious and may need urgent treatment.
How common are they?
Every year an estimated 2000 malignant brain tumours are diagnosed in Australia. Malignant spinal cord tumours are rare. About 55 people are diagnosed with malignant spinal cord or other central nervous system tumours each year. 1
Benign brain and spinal cord tumours are more common than malignant tumours. Data is not collected Australiawide, but in 2013, there were more than 1000 benign brain and spinal cord tumours in Victoria, Queensland and Western Australia combined. 1
What types are there?
There are more than 40 types of primary brain and spinal cord tumours (also called central nervous system or CNS tumours). They are classified based on the type of cell (as seen under a microscope) and how the cells are likely to behave (based on their genetic make-up). Doctors use this classification to work out the best treatment.
Most common types of primary brain tumours
- starts in glial cells
- common category of brain cancer
- different types of glioma grow from different types of glial cells (see next four rows)
- a type of glioma
- starts in glial cells called astrocytes
- a type of fast-growing (high-grade) astrocytoma
- makes up more than half of all gliomas
- a type of glioma
- starts in glial cells called oligodendroglia
- a type of glioma
- starts in glial cells called ependymas more common in children than adults
- a high-grade tumour that starts in the cerebellum
- rare in adults but more common in children
- starts in the membranes (meninges) covering
- the brain and spinal cord
- common primary brain tumour, often low-grade
- starts in Schwann cells, which surround nerves in the brain, and is usually low-grade
- includes acoustic neuromas
Secondary cancer in the brain
A tumour that begins as a primary cancer in another part of the body before spreading to the brain is known as a secondary cancer or metastasis. The most common cancers to spread to the brain are melanoma, lung, breast, kidney and bowel.
What are the risk factors?
The causes of most brain and spinal cord tumours are unknown. However, there are a couple of known risk factors for brain tumours:
In rare cases, a fault in the genes, usually passed down from one parent, can increase the risk of developing a brain tumour. For example, some people have a genetic condition called neurofibromatosis, which can lead to tumours of the neurons.
In rare cases, people who have had radiation therapy to the head, particularly to treat childhood leukaemia, may be at an increased risk of developing a tumour.
Mobile phones and microwave ovens
Many people are concerned that electromagnetic radiation from mobile phones or microwave ovens may cause brain cancer. Evidence to date does not show that mobile phone use causes cancer. However, if you are concerned about potential harm from mobile phones, you may choose to use a headset, limit the time you spend on your mobile phone or consider texting rather than calling.
Microwave ovens have been in widespread use since the 1980s. There is no evidence that ovens in good working order release electromagnetic radiation at levels harmful to humans.
What are the symptoms?
In some cases, a brain tumour grows slowly and symptoms develop gradually, so you may not be aware that anything is wrong at first. In other cases, symptoms appear suddenly.
Many symptoms of brain tumours are more likely to be caused by other factors. However, any new, persistent or worsening symptoms should be reported to your doctor.
Brain tumour symptoms may be caused by increased pressure in the skull (intracranial pressure). Pressure can build up because the tumour itself is taking up too much space or because it is blocking the flow of cerebrospinal fluid around the brain.
Intracranial pressure can lead to symptoms such as:
- headaches – often worse when you wake up
- nausea and vomiting – often worse in the morning or after
- changing position (e.g. moving from sitting to standing)
- confusion and irritability
- blurred or double vision
- seizures (fits) – can be obvious, involving a loss of consciousness, or more subtle, such as "zoning out"
- weakness in parts of the body
- drowsiness – a later symptom.
Symptoms caused by tumour position
Other symptoms relate to where in the brain or spinal cord the tumour is located – see below.
Common tumour symptoms
Some brain tumour symptoms depend on where the tumour is located. See above for general symptoms caused by pressure in the skull.
- difficulty with planning or organising
- changes in behaviour, personality and social skills
- depression or mood swings
- weakness in part of the face, or on one side of the body
- difficulty walking
- loss of sense of smell
- sight or speech problems
- trouble finding the right word
- forgetting events and conversations
- difficulty understanding what is said to you
- trouble learning and remembering new information
- seizures with strange feelings, smells or deja vu
- loss of vision (often peripheral vision)
- nausea or vomiting
- erection problems
- less interest in sex
- thyroid and other hormone changes
- coordination problems
- difficulty swallowing or speaking
- double vision
- facial weakness and numbness
- weakness and fatigue
- changes to sleep/ wake patterns
- weakness in arm or leg
- personality changes or confusion
- problems with reading or writing
- loss of feeling in part of the body
- difficulty with spatial awareness, e.g. telling left from right, locating objects
- loss of all or some vision
- back and neck pain
- numbness or tingling in the arms or legs
- clumsiness or difficulty walking
- loss of bowel or bladder control (incontinence)
- coordination and balance problems
- uncontrolled eye movement
- stiff neck
- difficulty speaking (staccato speech)
Which health professionals will I see?
If your general practitioner (GP) or another doctor suspects that you have a brain or spinal cord tumour, they will arrange the first tests to assess your symptoms. You will then be referred to a neurosurgeon, neurologist or neuro-oncologist, who will examine you and may do more tests.
If a tumour is diagnosed, the specialist will consider your treatment options. Often these will be discussed with other health professionals at what is known as a multidisciplinary team (MDT) meeting. During and after treatment, you will see a range of health professionals who specialise in different aspects of your care.
| Health professional
||diagnoses and performs surgery for diseases and injuries of the brain and nervous system
||diagnoses and treats diseases of the brain and nervous system that do not need surgery
||diagnoses and treats tumours of the brain and nervous system; a neuro-oncologist may be a neurologist, medical oncologist or neurosurgeon
|cancer care coordinator
||coordinates your care, liaises with other members of the MDT and is an ongoing contact for you and your family
throughout treatment; may also be a called a clinical nurse consultant (CNC) or clinical nurse specialist (CNS)
||administers drugs and provides care, information and support throughout treatment
||treats cancer with drug therapies such as chemotherapy, targeted therapy and immunotherapy
||treats cancer by prescribing and overseeing a course of radiation therapy
||analyses tissue from brain or spinal cord tumours to identify the tumour type
||recommends an eating plan for you to follow while you are in treatment and recovery
||links you to support services and helps you with emotional, practical or financial issues
||assesses people with problems in thinking or behaviour caused by illness or injury (particularly to the brain) and manages their rehabilitation
||help you manage your emotional response to diagnosis and treatment
||recommends and oversees treatment to help you recover movement, mobility and speech after treatment and return to daily life
|physiotherapist, occupational therapist, speech therapist
||assist with physical and practical problems, including restoring movement, mobility and speech after treatment, and recommending aids and equipment
Childhood brain tumours
In Australia, more than 100 children under 15 are diagnosed with a malignant brain or spinal cord tumour each year. 1 Children are more likely to develop tumours in the lower part of the brain, which includes the areas that control sleep/wake functions, movement and coordination. Gliomas and medulloblastomas are the most common types.
In general, children diagnosed with a malignant tumour will have a better outlook than adults. In many children, treatment will cause all signs of the cancer to disappear (remission). Because a child's nervous system is still developing, some children may have a physical, behavioural or learning disability as a result of the tumour or treatment.
Many health care professionals specialise in treating children and young adults (paediatrics). Some hospitals have staff, such as play therapists, music therapists or art therapists, who can help children cope with the challenges of treatment. Rehabilitation will also be important for your child's recovery.
Talk to your child's medical team about treatment options, what to expect, and your concerns. The hospital social worker can provide practical and emotional support.
Organisations like Camp Quality, CanTeen and Redkite offer support for families, young adults and children affected by cancer. Redkite offers a print and online picture book called Mary has a brain tumour that you can read with your child.
As a parent, it may be helpful to read Cancer Council's Talking to Kids About Cancer. Call 13 11 20 for more information.
Expert content reviewers:
Dr Brindha Shivalingam, Neurosurgeon, Chris O'Brien Lifehouse, NSW; Conjoint A/Prof Andrew Cole, University of New South Wales, Senior Staff Specialist and Director, Cancer Rehabilitation Service, Greenwich Hospital Rehabilitation Service, and Chief Medical Officer, HammondCare, NSW; Laraine Cross, Senior Clinician, Social Work and Psychosocial Oncology Services, Calvary Mater Newcastle, NSW; Dr Anthony Dowling, Medical Oncologist, St Vincent's Hospital Melbourne, VIC; Kate Fernandez, 13 11 20 Consultant, Cancer Council SA; Ian Gelling, Consumer; Anne King, Cancer Nurse Coordinator Neuro-oncology, WA Cancer and Palliative Care Network, WA; Jodie Nixon, Team Leader Cancer Occupational Therapy, Princess Alexandra Hospital, Brisbane, QLD; Prof Tamara Ownsworth, School of Applied Psychology, Griffith University, QLD; Dr Claire Phillips, Radiation Oncologist, Breast and Neuro-oncology, Peter MacCallum Cancer Centre, VIC.
1. Australian Institute of Health and Welfare (AIHW), Brain and other central nervous system cancers, AIHW, Canberra, 2017.