Numerous children are diagnosed with cancer every day, September marks the International Childhood Cancer Awareness Month. During this time, the spotlight is on cancer among children and the requirement to improve the quality of diagnosis, treatment as well as outcomes. Brain cancer (tumour) is the most common solid organ cancer in children.
As per the National Centre for Disease Informatics and Research (NCDIR), India, the annual incidence of pediatric brain tumours is 1 to 2 per 100,000 children. This incidence is increasing globally in recent years, partly due to improvement in diagnostic aids like CT scan/MRI, increased public awareness and better clinical practices but also due to changes in potential risk factors.
Like other cancers, brain tumours are also caused by uncontrolled growth and multiplication of cells, caused by a change or mutation in the DNA. The possible factors which may bring about this DNA mutation in case of brain tumours include ionizing radiation, hereditary/ familial predisposition and genetic syndromes. A high level of parental occupational exposure to pesticides may be associated with an excess risk of brain tumours in children as per an article published in BMC Cancer on 28 August 2020, Switzerland National Registry. Parental age at childbirth also has a potential role. Especially with respect to adolescent females, hormonal factors and obesity have been associated with increased risk of benign brain tumours like meningiomas. Certain infections and immune-mediated conditions are other possible factors.
What is Medulloblastoma?
The commonest primary brain tumours in children are embryonal tumours (medulloblastoma), ependymoma, meningioma, glioma and craniopharyngioma. Embryonal tumours occur with a global incidence of 0.6 to 0.8 per 100,000 children, of which Medulloblastoma constitutes 0.2 to 0.6 per 100,000 children. In India, the majority of medulloblastomas occur between the ages of 3 to 20 years, with the average age of diagnosis being 10 years. It constitutes about 20% of all pediatric brain tumours. Common symptoms may include early morning vomiting, headache, eye disturbance, imbalance on walking and speech abnormality.
Diagnostic evaluation for Medulloblastoma requires MRI of the brain and spine and examination of the cerebrospinal fluid. Definitive diagnosis is established after surgical removal of the tumour and detailed examination of the surgical specimen by a trained neuro-pathologist. After surgery, radiation therapy to the entire brain and spinal column (craniospinal irradiation) is required to prevent recurrence and can cure >85% children after complete resection, if no spinal cord involvement is present. Additional chemotherapy may be required in cases having a higher risk of metastasis. Important factors that govern the likelihood of disease control and survival (prognosis) in a particular case include the age of the child, the status of surgical removal of the tumour (complete or partial removal) and the presence or absence of spread of the tumour in the cerebrospinal fluid. Recently, a molecular classification segregating medulloblastomas into distinct molecular subgroups has become available, which provides additional information about the prognosis.
Early diagnosis and correct treatment, instituted at the right time, goes a long way in curing a child with a brain tumour. Tender loving care, emotional support, physiotherapy, educational support and rehabilitation play extremely crucial roles in helping such children to regain vital body functions and improve their quality of life.
Dr Tejinder Kataria is Chairperson at Cancer Institute, Medanta- The Medicity, Gurugram. Dr Kushal Narang is Associate Consultant at Cancer Institute, MedantaThe Medicity, Gurugram.