Primary brain tumours
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Dr Daleen Geldenhuys educates us on how primary brain tumours are diagnosed and treated.
Tumours of the central nervous system are divided into distinct groups and varies in presentation and prognosis. There are benign and malignant tumours affecting the brain. Malignant tumours of the brain can be subdivided into primary tumours that start in the brain versus secondary tumours that have metastasised from other primary cancers, such as lung, colon, breast and others. Some of the symptoms and signs of both primary and secondary brain tumours overlap.
Primary brain tumours
Primary brain tumours originate from the tissues of the brain or the brain’s immediate surroundings. Primary tumours are categorised as glial (composed of glial cells) or non-glial (developed on or in the structures of the brain, including nerves, blood vessels and glands).
Most primary brain tumours in adults are sporadic, with no identifiable risk factors. Aside from relatively rare genetic syndromes, such as neurofibromatosis and cancer predisposition syndromes (Li-Fraumeni), the only established risk factor for primary brain tumours is exposure to ionizing radiation.
Signs and symptoms
Brain tumours produce signs and symptoms by local brain invasion, compression of adjacent structures and increased intracranial pressure (ICP). The clinical manifestations are determined by the function of the involved areas of brain. For example, if it’s in the cerebellum (smaller part of the brain), balance and intention tremors may be the presentation symptoms. If it grows in the frontal lobes of the brain, personality changes may be the presenting symptoms. It may easily be confused with a stroke or cerebrovascular accident if the symptoms are that of weakness of either side of the body.
New onset severe headaches and projectile vomiting are symptoms of raised pressure inside the head and may accompany any of the other symptoms. A depressed level of consciousness and new onset seizures should always be investigated.
A diagnosis is made after careful history and examination, correct imaging, and histological confirmation. The MRI is an important tool in making the diagnosis and surgical planning for patients.
Accurate diagnosis of a brain tumour requires an adequate tissue sample for histopathologic and molecular studies. This may be obtained by stereotactic biopsy or open surgery. Procedure selection is individualised based on the suspected tumour type and grade, location, and operability.
Primary brain tumours usually present as a single lesion and surgical removal is the best treatment followed by possible radiation and oral chemotherapy to preventba recurrence.
Some slow-growing non-cancerous tumours can be followed up by regular scanning and may never progress or need intervention.
Treatment needs to be individualised and may include several modalities of treatment. Surgical removal of the tumours is preferred, if it’s possible without too many sequelae, such as neurological deficits post-operatively.
Radiation, as adjuvant therapy, with or without oral chemotherapy may be indicated. Stereotactic radiation (Gamma Knife surgery) can be used especially if there is a single recurrence or if the patient is not a surgical candidate.
Combined-modality therapy is the standard of care for younger patients with an aggressive histology, but with advancing age the benefits become more closely balanced with risks of toxicity and side effects of all the therapies involved. Single-modality therapy is often better tolerated and is a common approach in older patients with a low functional status.
Other therapies available for recurrent brain tumours include oral chemotherapy (temozolamide), anti-vascular proliferative agents (bevacizumab) and intravenous chemotherapy.
The best outcome for patients with brain tumours depend on a quick and accurate diagnosis and initiation of therapy. A multi-disciplinary team is vital for the treatment and recovery of this most-feared tumour and include not only specialist doctors but also other medical professionals such as occupational and physiotherapists.
MEET THE EXPERT – Dr Daleen Geldenhuys
Dr Daleen Geldenhuys is a specialist physician and medical oncologist who works at West Rand Oncology Centre at Flora Clinic. She treats patients with all types of cancer and enjoys clinical research, and is a member of SASMO, SASTECS, ESMO and ENETS.
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