Brain Tumors in Children: What are they?

Definition

Pediatric brain tumors are a highly heterogeneous group of diseases, distinct from those in adults and far less common. Diagnosing a pediatric brain tumor can be challenging due to the existence of more than fifteen different histological types.

The incidence of pediatric brain tumors is slightly higher in boys than in girls and is more prevalent in young children.

They include medulloblastomas and ependymomas.

Medulloblastoma

Medulloblastoma, the most frequent pediatric brain tumor, originates in the cerebellum. Due to DNA alterations, some healthy nerve cells degenerate into cancer cells and begin to multiply uncontrollably.

The 5-year survival rate for medulloblastoma after diagnosis is approximately 60-70%.

Ependymomas

Ependymomas are part of a group of tumors called gliomas that primarily appear within the first six years of life. Collectively, they represent 10% of all childhood central nervous system tumors.

5-year survival after diagnosis varies depending on the grade of the ependymoma and, in the most favorable cases, can reach 75%.

Relapses beyond 5 years are not uncommon.

Recognizing a Brain Tumor in a Child

Symptoms of Brain Tumors in Children

Brain tumors can develop progressively or suddenly. Possible symptoms include headaches, nausea, vomiting, blurred vision, balance problems, behavioral changes, seizures, drowsiness, and largely depend on increased pressure inside the skull (intracranial pressure).

In young children, irritability, loss of appetite, developmental delays, sudden loss of motor or intellectual skills, and increased head size may also be observed. In school-aged children, decreased school performance and fatigue may be observed.

The precise location of the tumor can lead to specific symptoms. For example, if the tumor develops in the area of the brain that controls speech, the child may have difficulty speaking or understanding words. A tumor developing in the spinal cord can cause back pain, weakness, lack of coordination in the legs and/or arms, as well as problems with bladder and bowel function.

Many symptoms are common to other less serious illnesses. If they do not disappear or worsen, it is important to talk to your doctor so that the cause can be identified quickly and accurately.

How is the diagnosis of pediatric brain tumors made?

Detecting pediatric brain tumors requires combining clinical diagnosis and radiological examinations, which utilize harmless and highly targeted imaging techniques, such as computed axial tomography and nuclear magnetic resonance.

Magnetic resonance imaging (MRI) allows visualization of internal structures, including tumors, using magnetic fields. MRI produces very precise images and involves no exposure to ionizing radiation. However, as the examination is quite lengthy and the patient must remain still, sedatives may be administered to children to help them sleep during the procedure.

Computed tomography (CT) uses X-rays to obtain images of internal tissues. CT scans are faster but less sensitive than MRI and expose patients to ionizing radiation.

To determine the type of tumor, if the location allows, neoplastic material must be obtained for morphological and molecular analysis to aid in treatment selection. If the neurosurgeon deems that the tumor can be wholly or largely removed, they will proceed with tumor removal after consultation with other specialists responsible for the patient's care, primarily the pediatric oncology expert, who will manage adjuvant treatment (radiotherapy) and subsequent follow-up.

Sometimes, the diagnosis can be made by performing a lumbar puncture to collect cerebrospinal fluid for microscopic examination.

Prognosis

Pediatric brain tumors necessitate a multidisciplinary therapeutic approach involving various professionals at each stage of care: neurosurgeon, neuroradiologist, neuropathologist, neuro-oncologist, neuropsychologist. Not all tumors require all therapeutic interventions, but holistic care for the young patient is essential.

While these tumors are common in children and their location is concerning, they are curable diseases with an overall survival rate (averaging all histologies) of about 70%. Despite this, central nervous system tumors remain a leading cause of childhood cancer mortality and a significant cause of permanent disability. Even with increasingly effective treatments, cured children often experience long-term neurological, endocrinological, and cognitive problems that may affect their quality of life.

Therefore, research aims to both increase the number of children cured of central nervous system tumors and improve their quality of life. To achieve this, pediatric neuro-oncology is advancing in numerous areas.

Treatment for Pediatric Brain Tumors

Improvements in surgical techniques, along with the use of advanced technologies such as neuronavigation, endoscopic surgery, neurological monitoring, and intraoperative radiological control, have reduced neurological damage related to surgery depending on the lesion's location.

A better understanding of the molecular characteristics of each tumor has led to the development of targeted therapies that, in principle, can specifically target tumor cells. This minimizes long-term side effects and increases treatment efficacy.

Based on the tumor's biological characteristics, it is now possible to test new drugs to determine their effectiveness, either alone or in combination with conventional therapies.

Radiotherapy techniques are also constantly evolving, both in terms of improved treatment planning to spare healthy tissues and in terms of experimentation with new particles and different methods of delivering radiant energy.