How To Prevent A Brain Tumor

What is a brain tumor?

A brain tumour refers to the growth of abnormal cells occurring within the brain, or the central nervous system (CNS). This happens when mutations (changes in a cell's DNA) occur within brain cells so they are unable to stop dividing, or divide at an accelerated rate. 

These abnormal cells accumulate as clumps or masses. As the brain is enclosed within the skull, there is very little room to accommodate this unregulated growth. This pressure impacts surrounding nerves and can lead to damage of the surrounding brain tissue.

Like other tumours, brain tumours can be either benign (non-cancerous), or malignant (cancerous). A benign tumour grows slowly and normally will typically not spread to other regions. A malignant tumour grows rapidly and the cells can spread (metastasise) to other surrounding brain tissue and to the central nervous system. 

Signs and symptoms of brain tumors

Brain tumours can cause varying symptoms depending on their location and i size. Some of these symptoms include; 

Headaches

Headaches are common, it can be difficult to differentiate between a tumour-related headache and other types of headache, such as migraines. However, you should speak to your health care provider if you experience; 

• The onset of a new headache
• Being woken up by a headache whilst sleeping
• Persistent headache unrelated to migraine pain
• Pain is more intense during the morning
• Pain is more intense when moving
• Unexplained vomiting with or without nausea (finding relief after being sick)
• Onset of other neurological symptoms
• Over-the-counter medication does not ease the pain

Seizures  

Can occur in ⅓ of patients. This happens when there is focal damage, however is not a definitive sign of a brain tumour. 

Location-based symptoms

The brain can be divided into specific regions for their differing functional roles. This includes the frontal lobe, parietal lobe, temporal lobe and occipital lobe. A tumour within one of these lobes can cause unique neurological symptoms. Examples of these symptoms are shown in the diagram below.

As tumours can cause a rapid onset of symptoms, it is advised to seek medical attention if these arise. However, it is important to remember that some symptoms are common with other conditions, and you should not suspect the worst outcome. Always ask a professional, and see your doctor if you are concerned with a sudden onset of new symptoms. 

What causes brain tumors?

Brain tumours occur when certain genes become damaged or are no longer active. In primary brain tumours, it may be difficult to determine a specific reason as to why this occurs but may be caused by genetic or environmental influences. 

Who is at risk?

Cancer research offers several risk factors for the causes of brain tumours, however you may not develop a brain tumour even if you fall into these categories. 

Family History. Having a family history of brain tumours may mean you have a genetic predisposition for developing one at some point in your life, however, this only accounts for a small proportion of people (around 5% of brain tumours). In these cases, those at risk may have a close family member, such as a parent or sibling who has also had a brain tumour. 

Cancer Research UK compiles a list of inherited cancer genes here.

Radiation exposure (particularly during childhood). Ionising radiation accounts for less than 1% of brain and other CNS tumours. This includes gamma rays, x-rays as used in diagnostics (such as X-rays or CT scans), or radiotherapy. Whilst some studies have identified no significant risk of medical ionising radiation in increasing brain tumour risk, low dose ionising radiation exposure to radiation should be used with discretion for diagnosis/treatment.^1,2 

Age. There is no defining age at which someone can develop a brain tumour. Some brain tumours develop in children and young adults, others during someone’s 40s-60s. However, research has shown an increased risk for those over the age of 75. 

Obesity. Research has shown a causal link between brain tumours and obesity-related inflammation, particularly in that of increasing risk of developing meningioma in obese females.³

Metastasis or previous cancer diagnosis. Metastasis occurs when cancer cells travel from one part of the body to another through the bloodstream or lymphatic system. Some cancers are more likely to spread to the brain causing secondary brain tumours, including; 

• Breast cancer
• Colon Cancer
• Kidney Cancer
• Lung Cancer
• Melanoma

Previous cancer diagnosis, particularly in children who have had childhood brain tumours or other solid tumours, may have a heightened risk.

How to diagnose a brain tumor?

Diagnostic options follow initial consultation with your health care provider. Questions about your symptoms, family history, and general overall health will provide key information as to whether a brain tumour is suspected before carrying on further testing. 

Physical exams such as a neurological exam and/or eye exam will allow fyour doctor to identify if there is any visible damage which may be due to  tumour growth. As the brain holds 12 major cranial nerves, your doctor will be able to spot whether there is any pressure potentially caused by a tumour affecting any one of these nerves.  

CT or MRI scan can provide a detailed image of your brain to detect  any type of tumour growth. 

Brain Angiography. This procedure checks for blood flow into a tumour and helps understand whether a tumour has grown over time. 

Biopsy. Your doctor may require a sample of tissue for further testing if there is a suspected mass. This may be offered as part of a craniotomy, which requires removing the tumour as part of a surgical operation, or a burr hole biopsy. This will then conclusively identify whether the tumour is benign or malignant.

What are the types of brain tumors?

Benign brain tumors

Tumours are categorised by their characteristics by the World Health Organisation, in what is known as a WHO grade. Benign tumours are low grade (WHO 1-2), whilst malignant tumours are high grade (WHO 3-4). 

Types of benign brain tumors

Gliomas are the most common type of adult brain tumour that occurs within the brain or spinal cord, affecting cells known as glial cells. Glial cells provide support to neurons within the brain and spinal cord, including astrocytes, oligodendrocytes, ependymal cells and microglia.  These occur in 30% of all brain tumours. Types of gliomas, such as astrocytomas and oligodendroglioma can have both benign and malignant forms. 

Circumscribed and diffuse astrocytomas are a type of tumour that begins within star-shaped cells known as astrocytes. These are important for multiple functions within the brain, such as the support of neurons and other maintenance roles.  There are two types of benign astrocytoma, pilocytic astrocytoma (WHO grade 1) and diffuse (low grade) astrocytoma (WHO grade 2). Astrocytomas are more common in children and young adults.

Oligodendroglial diffuse glioma is the third most common glioma, found mainly within the frontal lobe of the brain.Low-grade, or slow growing tumours are formed from oligodendrocytes occur in around 5% of brain tumours, affecting mainly those between the ages of 30-60. 

Meningiomas are the most common benign brain tumours which occur during adulthood, with tumours that are attached to the inner surface of the brain's meninges. This includes WHO grade 1 and 2 meningiomas, which make up around 10-25% of all primary brain tumours⁴. These tumours can also be malignant, but most are benign.

Schwannomas are also very common brain tumours affecting adults in their 30s-40s but can be diagnosed in children. 

Pituitary adenomas are the third most common brain tumour, at around 10% or all brain tumours, arise in the pituitary gland. These are more common in those in their 30s-40s, rarely occurring in those in their 20s. 

Other types of benign tumours include, 

• Choroid plexus tumours (Choroid plexus papilloma, Atypical choroid plexus papilloma) 
• Craniopharynigiomas
• Ependymal tumours (Ependymoma, Myxopapillary ependymoma, Subependymoma)
• Gangliocytoma
• Glomus jugulare tumours 
• Pineocytomas 

Cancerous (malignant) brain tumors

Cancerous tumours, or “high grade” tumours, are more aggressive and have a higher likelihood of spreading. These types of tumours are more serious than low grade, due to them being much harder to remove, more likely to grow back and metastatic. However, gliomas such as astrocytomas, oligodendrocytes, and ependymal tumours can have malignant forms if graded 3-4, including;

• Anaplastic astrocytoma
• Glioblastoma multiforme
• Anaplastic oligodendrocytoma 
• Anaplastic ependymoma

For more information regarding tumours and rare tumours visit Brain Tumour research.  

How common are primary brain tumors?

• According to Cancer Research UK, primary brain tumours (tumours which start in the brain or spinal cord) make up around 3% of total cancer cases, with 12288 new cases per year in the UK
• In the United states, the incidence rate is around 23.8 adults per 100,000
• According to the American health society, the chance of developing a malignant brain tumour is 1%.
• In the UK, malignant tumours typically occur in 2% of all adult cancers, with approximately 4400 people diagnosed each year

How serious are brain tumors?

The severity of a brain tumour depends on its location within the brain or CNS, what size it is and its WHO grade. Some brain tumours can be life-threatening. The quicker this is diagnosed is very important to begin treatment and increase life expectancy (in that of malignant cases). Many charities offer guidance for those diagnosed with brain tumours.

How are brain tumors treated?

Treatment for brain tumours depends on its location, its size and tumour type. There are various treatment options, which can be used in combination to increase chances of survival.  

Surgery

Brain surgery is an operation that aims to remove as many tumour cells as possible, with an optimal outcome of removing the mass entirely. In some cases, the tumour may be inoperable, however, there are other options which can be explored. 

Radiation therapy

Radiotherapy is a common treatment option for malignant brain tumours alongside surgery. Radiation therapy can stop the growth of the tumour and minimise/ or eliminate neurological symptoms. 

Chemotherapy

Chemotherapy refers to the use of administered drugs to kill tumour cells and is only offered when a tumour is malignant. 

Stereotactic surgery 

This type of surgery uses precise beams of radiation targeted at the tumour, whilst minimising radiation dose to surrounding brain tissue.  This procedure has been noted for being less invasive and can be used as a primary treatment option. 

Clinical trials

Experimental treatments tested in clinical trials may be beneficial in some cases. It is important to consult medical professionals, as there is always the possibility that the treatment may not be as effective as standard treatment options. 

Can brain tumors be prevented?

According to Cancer Research UK, only 3% of brain and CNS tumour cases are preventable. This is attributed to those exposed to ionising radiation, however, procedures using radiation (such as X-rays) will only be used for a limited, necessary amount of time. 

However, maintaining a healthy lifestyle may help in reading the risk of other types of cancer in the future.

When to seek medical attention?

As brain tumours present neurological symptoms, it is important to seek medical advice if you feel concerned about the onset of new symptoms. 

Summary

• Brain tumours present serious neurological symptoms 
• Brain tumours are rare
• Preventable brain tumours make up a very small percentage of cases
• Seek medical attention if you are concerned with the onset of new symptoms, as described above.