What are brain or spinal cord tumours?
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.
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.
Learn more about:
- The brain and spinal cord
- Who gets brain or spinal cord tumours?
- Types of brain and spinal cord tumours
- What causes brain or spinal cord tumours?
- Video: What is brain cancer?
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 – 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.
Spinal cord – 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.
Meninges – Both the brain and spinal cord are surrounded by thin layers of protective tissue (membranes) called the meninges.
Cerebrospinal fluid – 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.
Pituitary gland – 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
|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.
Corpus callosum – 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 opposite.
The parts of the brain
Who gets brain or spinal cord tumours?
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.
Benign brain and spinal cord tumours are more common than malignant tumours. Data is not collected Australia-wide, but in 2013, there were more than 1000 benign brain and spinal cord tumours in Victoria, Queensland and Western Australia combined.
Types of brain and spinal cord tumours
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 the pituitary gland
- almost always 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 causes brain or spinal cord tumours?
The causes of most brain and spinal cord tumours are unknown. However, there are a couple of known risk factors for brain tumours:
- Family history – 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.
- Radiation therapy – 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.