Secondary brain tumours
A secondary brain tumour (metastasis) is a tumour growing within the brain that has arisen from the spread of a malignant tumour (cancer) elsewhere in the body. These tumours have formed from cells that have broken away from the primary tumour and have spread in the bloodstream to the brain. The common primary source is a lung or breast cancer, but they can arise from bowel, kidney, skin and other cancers.
How will the diagnosis be made?
If your brain scan has shown a suspected metastasis, your doctors may arrange a series of investigations to identify a possible primary tumour (or other metastases elsewhere in the body). This will include a full clinical examination (including breast exam in women), chest X-ray, blood tests and sometimes CT of the chest abdomen and pelvis.
If a primary source is identified it may be possible to biopsy or remove this tumour to confirm the diagnosis, and other treatment may be needed for the primary tumour. If it is not possible to identify a primary tumour you will usually be advised that the secondary brain tumour will need to be biopsied or removed to determine the diagnosis.
What is the best treatment for my tumour?
The best treatment for you depends on many factors including:
- Location – if the brain metastasis lies near the surface and in a ‘safe’ area of brain your surgeon might advise an operation to remove the tumour. If an important part of the brain is involved it may not be possible to remove it safely.
- Number – the more brain metastases there are, the less likely it is to be able to remove them all.
- Type of tumour – some tumour types respond better to radiotherapy or chemotherapy than others.
- Where else the tumour is – you may require treatment for your primary tumour or any other metastases elsewhere in the body.
- Your general health – for example there may be risks with a general anaesthetic in patients with other significant medical conditions, such as heart disease.
The best treatment, therefore, varies from one patient to another. For some patients there may be no need for any treatment at all; in others it may be advisable to have a combination of treatments such as surgery, radiotherapy and chemotherapy.
Who decides on the best treatment for me?
The best treatment for each patient is determined by a panel of specialists call a multi-disciplinary team, consisting of neurosurgeons (with specific expertise in brain tumours), neuro-oncologists (specialists in radiotherapy and chemotherapy), neuroradiologists (specialist in interpreting brain scans) and neuropathologists (make the diagnosis by examining the biopsies under the microscope). This opinion will be discussed with the patient by his treating doctors but ultimately, only the patient can decide which treatments he wishes to undergo.
What normally happens?
If your scan is suspicious for a secondary brain tumour, your doctors will initially usually perform investigations to identify a possible primary or other secondary lesion. Dependent on these investigations, they may then refer you to a neurosurgeon who will discuss your case with the multi-disciplinary team. If you are likely to require neurosurgery, you will then have a consultation with a neurosurgeon who will advise you of the treatment options. You may require surgery to obtain a diagnosis with a biopsy or for removal of a secondary tumour.
In some patients, surgical tumour removal may not be possible, for example for tumours in vital areas of the brain. For such tumours (if less than 3cm in diameter) it may be possible to treat with stereotactic (targeted) radiosurgery.
If you have a confirmed brain metastasis you will then be referred to an oncologist for consideration of whole brain radiotherapy. This is important even in patients who have had surgery to remove a tumour (or radiosurgery) as there may be further ‘micro-metastases’ elsewhere in the brain that were too small to be seen on your initial scans.
You may require treatment for your primary tumour or other metastases under the care of an oncologist.
What is the prognosis?
The prognosis (likely outcome of your treatment) depends on the type and extent of the primary tumour, and the number and location of the metastases in the brain and elsewhere in the body. It is also influenced by age, general health and your symptoms. Your oncologist will be able to give you a clearer idea of prognosis when the final diagnosis has been made and investigations have established the extent of the primary tumour and any metastases.