Mummy, I have a headache...
Brain tumours are among the most common childhood malignancies and they vary widely in their type, location and growth rate.
“MY child was complaining of persistent early morning headaches and vomiting for about two to three weeks.
“We put it down to stress and adjustment problems as she had just started her schooling. But we began to be quite concerned when her speech became slurred and her gait became wobbly.
“When we brought her to a doctor, an urgent brain scan was arranged.
“To our surprise, we were told that she had a brain tumour that required surgery urgently.
“It was a mixture of shock and disbelief hearing those words. There was just this whole mess of thoughts in our heads.”
This is a common scenario we encounter when we attempt to break the news of a brain tumour to parents.
However, even though the diagnosis of a brain tumour is devastating and the journey is full of challenges, there is still hope for cure in certain brain tumour subtypes.
Incidence and brain tumour subtypes
In Malaysia, brain (central nervous system, CNS) tumours are the second most common cancer in children, comprising 10%– 15% of all paediatric malignancies, with an overall incidence of 9.9 cases per million per year.
Brain tumours can either be benign or malignant, and different histological sub- types are present in children compared to adults.
There is a small peak in incidence in early childhood accounted for by medulloblastomas and germ cell tumours near the time of puberty.
Unfortunately, symptoms and signs of brain cancer vary widely and depend on which part of the brain the tumour is pressing on.
These clinical manifestations are non-specific and can occur in many other diseases.
Although headache is often the first symptom, parents should understand that most headaches are not due to brain cancer.
The sinister headaches are those that are severe, persistent or recurrent, and warrant urgent medical review.
Other features of concern are nausea and vomiting, difficulty in speaking, blurring of vision, hearing loss, facial asymmetry, squint, limb weakness or numbness, loss of balance, drowsiness, a change in personality, seizures and loss of memory.
In younger children (less than a year old), general irritability, increasing head circumference and delayed developmental milestones are important features.
Multimodal treatment approach
Surgery is the first-line treatment for most brain tumours, and there has been rapid technological advances, including the use of cortical mapping and Imaged Guided Surgery (IGS).
These techniques allow neurosurgeons to identify areas that control the senses, language and motor skills, as well as map out the tumour location very accurately.
However, sometimes, the tumour is inoperable if it is located near vital structures, and in this situation, other treatment options (for example, chemotherapy or radiotherapy) will be considered in the first instance.
Radiotherapy plays a key role in treating brain tumours.
Depending on the size and location of the tumour, a radiation oncologist will choose the best option or combination of radiation techniques to achieve maximal benefit with minimal collateral damage.
Radiation is associated with potential short-term and long-term side effects. The long-term side effects of radiation depend on the extent of the radiation field and include hormonal, growth and memory and cognitive problems, such as difficulty understanding and performing complex tasks.
Therefore, early involvement of the endocrinologist and neuro-psychologist are crucial in the management of children with brain cancer.
Given the potential complications of radiation, there are several ongoing clinical trials looking at reduced-dose radiotherapy in order to minimise the risk for deleterious neurocognitive impairment in survivors without compromising the outcome.
Cranio-spinal (brain and spine) radiotherapy is avoided in children younger than three years of age because of greater vulnerability of the developing brain to treatment-related toxicity.
Chemotherapy has been used widely in the treatment of childhood brain tumours, especially in infants, in an attempt to delay radiotherapy, and in older children with certain brain tumour subtypes that are responsive to cytotoxic agents.
Unfortunately, not all brain tumours will respond to chemotherapy or radiotherapy. For example, disappointing results have been observed in childhood high-grade glioma and the majority of affected children have succumbed due to incurable disease.
Hence, it is extremely challenging to develop a “one-size-fits-all” treatment strategy for childhood brain tumours, given their clinical variability and molecular heterogeneity.
Current status of brain tumour management in Malaysia
middle-income countries varies based on the availability of healthcare resources and choice of treatment regimens.
In many developing countries, the ability to offer multimodal treatment based on molecular subgroups of brain tumours is still lacking.
In Malaysia, the five-year overall survival rate of average-risk medulloblastoma is 58%, compared to 80% in high-income countries, and no data exists on the relevance of the molecular subgroups of childhood brain tumours.
Limited healthcare facilities, inadequate financial support for brain tumour diagnostic tests and research activities, lack of a multidisciplinary neuro-oncology team, insufficient data in the National Cancer Registry, and inadequate long-term followup and cultural beliefs leading to treatment abandonment are the major contributing factors for this inferior outcome.
Healthcare facilities and technologies in Malaysia have improved dramatically over the years, leading to an increasing trend of survival in children with brain tumours.
However, further development is required. The genomic era has advanced our understanding of disease biology and identified distinct molecular subgroups using specialised diagnostic tests such as gene expression and DNA methylation analysis.
Given that modern treatment of childhood brain tumours will require risk stratification of patients according to specific subgroups, the ability to perform detailed molecular analysis would be a critical first step to improving care of these patients in Malaysia.
Research collaboration with developed countries are currently underway to improve the overall outcome of childhood brain tumours in the future. Dr Revathi Rajagopal is a paediatric oncologist specialising in the management of childhood brain tumours. This article is courtesy of the Malaysian Association of Paediatric Surgery. For further information, e-mail starhealth@ thestar. com.my. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.