Astrocytomas: what, where, how?

Dr Cathryn Walton explains how astrocytomas, a type of brain cancer, develop and how they are treated.

Receiving a diagnosis of a brain tumour can be an overwhelming experience, filled with great anxiety and uncertainty of what now? One of the most common types is the astrocytoma; they form 50% of all brain tumours diagnosed.  

What is an astrocytoma?

An astrocytoma is a tumour that grows from brain cells called astrocytes; these are the cells in the brain that act as the dedicated support crew for the brain’s main cells, the nerve cells (neurons). Astrocytes are star-shaped cells that provide nutrients, support and protection to the neurons, and so help the brain function correctly. 

An astrocytoma develops when these astrocyte cells begin to grow and divide uncontrollably, forming a mass called a tumour. Tumours put pressure on the normal brain which causes the brain to struggle to function correctly.

Astrocytomas are part of a broader group of brain tumours called gliomas, which are tumours of the glial (support) cells in the brain. Astrocytomas can vary significantly; some are slow-growing and relatively contained, while others are aggressive and can spread into surrounding brain tissue.

The grading system

To understand how an astrocytoma might behave and to plan the best course of treatment, doctors use a grading system established by the World Health Organisation (WHO). Tumours are graded from 1 to 4 based on how abnormal the cells look under a microscope.

Grade 1 (pilocytic astrocytoma): These are slow-growing, have clear borders, and are considered non-cancerous. They are most common in children and young adults and can often be cured with surgery alone.

Grade 2 (diffuse astrocytoma): Also slow-growing, but their edges tend to blend into the surrounding brain tissue, making them more difficult to remove completely. They have the potential to become more aggressive over time.

Grade 3 (anaplastic astrocytoma): These are cancerous (malignant) tumours. The cells are more abnormal and grow more rapidly than lower-grade tumours, actively invading nearby brain tissue.

Grade 4 (glioblastoma): This is the most common and most aggressive type of astrocytoma. These cancerous tumours grow very quickly, have a rich blood supply, and are very challenging to treat.

Symptoms

The symptoms depend entirely on its size and, crucially, its location in the brain, as different parts of the brain control different functions. It’s important to remember that these symptoms can also be caused by many other conditions. So, the symptoms are often ignored or assumed to be just part of life and stress. 

• Persistent headaches, which may be worse in the morning
• Seizures (first onset of seizures in adults must always be evaluated with a brain scan)
• Nausea and vomiting
• Changes in mood, personality, or concentration
• Memory problems
• Weakness, numbness, or tingling in an arm or leg
• Difficulties with speech or understanding others
• Vision problems (blurred or double vision)
• Balance problems or clumsiness

Treatment 

Treatment is highly-personalised and depends on the tumour’s grade, size, location, and your overall health. A team of specialists, including neurosurgeons, oncologists, and radiologists, will collaborate to create a treatment plan.

Surgery: This is often the first step. The goal is to remove as much of the tumour as possible without harming healthy brain tissue. For Grade 1 tumours, surgery might be the only treatment needed.

Radiotherapy: This uses high-energy rays to target and destroy any remaining cancer cells after surgery or to treat tumours that can’t be surgically removed.

Chemotherapy: This involves using powerful drugs to kill cancer cells. It can be given as a pill or through an intravenous (IV) drip and is often used alongside radiotherapy for higher-grade tumours and often after the radiotherapy to maintain efficacy of the management (keep it away for longer) .

Targeted therapy and other treatments: Newer treatments are being developed that target specific genetic mutations within the tumour cells, offering a more precise way to fight the cancer while sparing healthy cells.

Survivorship

Life after an astrocytoma diagnosis is a journey of recovery and adaptation. Survivorship begins at diagnosis and continues throughout your life. It focuses on managing the long-term effects of the tumour and its treatment to ensure the best possible quality of life.

Follow-up care is crucial. Regular MRI scans are needed to monitor for any signs of tumour recurrence. Rehabilitation may be necessary to regain skills affected by the tumour or its treatment. This can include physiotherapy to improve strength and balance, occupational therapy to help with daily activities, and speech therapy.

Living with the knowledge of a brain tumour can also take an emotional toll. Psychological support from counsellors, support groups, and loved ones is a vital part of the recovery process, helping you and your family navigate the challenges and uncertainties ahead.

Dr Cathryn Walton first practiced as a GP for 10 years; she then qualified as clinical oncologist in 2015 and was in a group practice. In 2023, she opened her own practice, Bay Oncology, in Gqeberha, Eastern Cape with primary focus on breast cancer, melanoma and other skin cancers, sarcoma, CNS malignancies, paediatric radiation, and radiation of benign conditions.

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