Brain Tumour: Causes, Symptoms, Diagnosis and Treatment

How do you get a brain tumour?

BRAIN TUMOUR SYMPTOMS

DIFFERENT TYPES OF PRIMARY BRAIN TUMOURS

Diagnosing Brain Tumour

Treating Brain Tumour

Side effects of brain tumour treatment

Not all tumours in the brain are cancerous.

A tumour, which is a mass of abnormal cells, can be either benign (non-cancerous) or malignant (cancerous). Brain cancer is diagnosed only when the tumour is malignant, spreading aggressively and invading adjacent areas in the brain and destroying the normal cells. A benign tumour typically remains localised but can still cause harm by compressing adjacent brain structures.

“A brain tumour doesn’t always originate in the brain. A tumour can develop in another part of the body and spread to the brain,” says Professor Ng Wai Hoe, Senior Consultant, Department of Neurosurgery at the National Neuroscience Institute (NNI), a member of the SingHealth group.

A tumour that originates in the brain is called a primary brain tumour, and one that originates elsewhere and spreads to the brain is called a secondary or metastatic tumour. Secondary brain tumours are cancerous and are unfortunately more common than primary ones.

How do you get a brain tumour?

The exact cause of a primary brain tumour is unknown. A secondary brain tumour is caused by cancer spreading from another part of the body. Doctors have identified some risk factors for developing a primary brain tumour. These risk factors include:

Age: The risk for brain tumour typically increases with age. People over the age of 65 have a higher risk.
Race: Caucasians are more prone to developing a brain tumour.
Gender: Males are prone to brain tumours.
Exposure to ionizing radiation: Radiation therapy for treating cancers such as leukaemia, and radiation exposure from atomic bombs.

“Genetic conditions such as neurofibromatosis and Li-Fraumeni syndrome increase your risk of developing a brain tumour and brain cancer. However, these account for a very small percentage of cases”, adds Prof Ng.

Mobile phones, power lines and microwave ovens have NOT been proven to be risk factors for developing a brain tumour.

BRAIN TUMOUR SYMPTOMS

Whether a tumour is benign or malignant, it can affect the normal functioning of the brain. Not all tumours present in the same way. Some don’t display symptoms initially, while others have symptoms that develop gradually.

Common brain tumour symptoms include:

- A change in headache pattern, with headaches becoming more frequent and severe, especially in the morning

- Blurring or vision abnormalities

- Unexplained nausea and vomiting

- Loss of appetite

- Weakness or loss of limb sensation and movement

- Difficulty with walking and balance

- New seizures

- Mood or personality changes

- Changes in memory, concentration, alertness

- Speech difficulty

- Hearing problems

The symptoms of a brain tumour are persistent and progressive.

“Many brain tumour symptoms can be caused by other illnesses too. It is therefore important to see a doctor if you have symptoms that persist or are bothersome,” says Prof Ng.

DIFFERENT TYPES OF PRIMARY BRAIN TUMOURS

A primary tumour can develop in the cells and membranes of the brain, the cranial nerves, pituitary gland or pineal gland. The most common types of primary brain tumours are:

Glioma: A glioma develops from the glial cells which keep the nerves healthy. Astrocytic tumours are the most common type of glioma.

Meningeal tumour or meningioma:This type of cancer forms in the meninges or membranes that cover the brain.

Medulloblastoma: This is a common type of malignant brain tumour in children. It usually develops in the cerebellum region of the brain.

Other types of brain tumours include pineal region tumour, acoustic neuroma and pituitary tumour.

Diagnosing Brain Tumour

Brain tumours are diagnosed based on various exams and tests, such as computed tomography (CT) scan, magnetic resonance imaging (MRI) and positron emission tomography (PET). A biopsy, in which a small tissue sample is taken, is carried out to determine if the tumour is benign or malignant. A malignant tumour means the patient has brain cancer.

Treating Brain Tumour

Treatment options depend on the type of tumour, its size and location and the patient’s general health. Therapy may also be given to reduce the risk of the tumour coming back. Treatment options include:

Surgery: The tumour can be entirely or partially removed, depending on its size, location and the risk involved. One advanced surgical procedure is awake craniotomy, performed while the patient is conscious. It is used to reduce the risk of neurological damage when the tumour is located in a critical brain region. “Surgery is the first line of treatment if the tumour, or part of it, can be safely removed. With current state-of-the-art technology such as advanced imaging, neuronavigation and intra-operative imaging, the safety of surgery has improved considerably,” says Prof Ng.
Radiation therapy: High-energy beams such as x-rays are used to destroy the tumour. Radiation therapy can be external (conventional radiation) or internal (brachytherapy).
Radiosurgery: Multiple precision radiation beams are focused on a small area of the tumour to shrink it or stop it from growing. Radiosurgery is non-invasive and painless, and usually done as an outpatient procedure.Doctors at SGH have been using the Novalis Shaped Beam Surgery machine to carry out radiosurgery for brain cancer patients since May 2007. “This treatment is particularly suitable for high-risk inoperable brain tumours. As it spares the surrounding healthy tissue, it reduces side effects from 20-30 per cent to 1-2 per cent,” says Prof Ng.
Chemotherapy: Drugs are administered in pill form or intravenously to destroy tumour cells.
Targeted drug therapy: Drugs focus on specific abnormalities within the tumour cell to destroy the entire cell.

These different brain tumour and brain cancer treatment methods can be used on their own or in combination. In some cases, such as a low-grade glioma which is not causing problems, treatment may not be required. The tumour may simply be left alone and closely monitored.

Brain tumour treatment typically involves a multidisciplinary team of specialists, including neurosurgeons, neurologists, medical oncologists, radiation oncologists, dietitians, psychologists, nurse clinicians and physical therapists.

Side effects of brain tumour treatment

Treatment for a brain tumour can have several side effects. These can range from fatigue, headaches and scalp irritation for radiation therapy, to brain damage in the case of surgery. Chemotherapy patients may experience nausea and hair loss, while those undergoing radiosurgery may have headaches and nausea.

Surgery for a tumour that is close to a nerve, or located in a critical or sensitive area of the brain may affect certain bodily functions such as vision, speech and movement. In this case, the patient may need the help of an occupational therapist and other specialists to regain normal function.

Ref : D24 (Edited)

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