Astrocytomas are tumors of brain and spinal cord that develop from astrocytes (a type of neuroglial cells that perform a protective and supportive function for neurons of central nervous system). Astrocytomas are the most common type of brain tumors in children, accounting for more than 50% of all neoplasms of central nervous system in children.
Depending on malignancy degree, there are 4 types of astrocytomas:
- Pilocytic astrocytoma (grade 1 malignancy). This is a benign tumor, grows slowly, and has clear boundaries. Favorite localization is cerebellum, optic nerves, brain stem. Most often diagnosed in children.
- Fibrillary astrocytoma (grade 2 malignancy). This is a relatively benign tumor without clear boundaries and grows slowly. Most often it develops in young people aged 20-30 years.
- Anaplastic astrocytoma (grade 3 malignancy). This is a malignant tumor that does not have clear boundaries; it grows quickly and invades the surrounding healthy brain tissue. Most often men aged 30-50 years are affected.
- Glioblastoma (grade 4 malignancy). This is the most malignant type of astrocytoma. It grows very quickly, has no clear boundaries, and grows into healthy nervous tissue of brain. Most often men aged 40-70 years are affected.
Pilocytic astrocytoma (or juvenile pilocytic astrocytoma) is the most common astrocytoma brain tumor in children. It has a low degree of malignancy and is localized mainly in cerebellum and visual pathways. The main type of treatment is surgery, which, unfortunately, cannot always be performed due to tumor location in brain.
If your child is diagnosed with astrocytoma, it is important to find a qualified oncologist, neurologist, ophthalmologist and neurosurgeon who has experience treating children with these brain tumors. These are the experienced specialists who work in Pediatric Oncology Department of Tel Aviv Medical Clinic.
Developing an examination plan and treatment regimen, TAMC doctors use only modern clinical recommendations and global treatment protocols. At the same time, the approach to each little patient is completely individual. Specialist takes into account all child characteristics and his illness, thanks to which it is possible to achieve success even in the most difficult situations.
An important feature of treatment at TAMC is the multidisciplinary approach. One patient with a brain tumor is assisted by a whole team of highly specialized doctors: oncologists, neurologists, neurosurgeons, radiation therapists, chemotherapists, rehabilitation specialists, physical therapists, speech therapists and other specialists if necessary.
Causes of astrocytoma in a child
Unfortunately, the exact reasons for astrocytoma development have not been established to date, but some factors are known that increase the risk of this brain tumor:
- Genetic factors – mutations in TP-53 gene, certain genetic diseases and syndromes, for example, neurofibromatosis type 1.
- Radiation exposure in past, for example a course of radiation therapy for another cancer.
- Negative influence of chemicals and other environmental factors.
- History of traumatic brain injury.
- Infection with certain viral infections.
- Age – each age category has its own types of astrocytoma.
Symptoms of astrocytoma in children
Clinical manifestations of astrocytoma primarily depend on which part of brain is affected (tumor localization): cerebral hemispheres, brain stem, spinal cord, cerebellum, visual pathways, hypothalamus. Symptoms also depend on child’s age, tumor size, and the rate of its growth.
Possible symptoms of astrocytoma in children:
- Headache that gets worse in the morning and is accompanied by nausea and/or vomiting.
- Various visual impairments.
- Loss of balance, change in gait.
- Sensory disturbances – weakness, numbness, tingling or changes in sensation on one side of the body.
- Changing the configuration of personality or behavior.
- Cramps.
- Speech impairment.
- Change in hearing.
- Unmotivated changes in body weight – decrease or increase.
- Symptoms associated with problems in functioning of endocrine system when tumor is localized in hypothalamus, for example, increased thirst or early puberty.
- Head enlargement in infants (hydrocephalus).
- An increase in size of fontanel, its bulging and pulsation.
- Focal neurological symptoms, depending on tumor location.
If there are any changes in baby’s health, do not hesitate! Seek professional help, and qualified TAMC specialists will help you quickly and efficiently understand any situation.
Modern diagnostic methods
Pediatric Oncology Department uses only modern, expert-class diagnostic equipment, making diagnostic process surprisingly comfortable and accurate. A feature of diagnostic program at TAMC is its complexity and speed. All necessary studies can be completed in one place within 3-5 working days.
A patient with suspected astrocytoma must be consulted by the leading pediatric oncologist of the department. Specialist conducts a thorough examination of child, collects anamnesis, studies complaints and identifies possible risk factors for pathology. Next, patient is examined by a pediatric neurologist and a pediatric ophthalmologist. Next, a multidisciplinary team of specialists creates a plan for child further examination, depending on the age and expected diagnosis.
Research methods for astrocytoma:
- Examination of neurological status.
- Complete ophthalmological examination.
- Necessary blood tests, for example, for hormones if damage to hypothalamus of brain is suspected.
- MRI with gadolinium and CT scan of brain and spinal cord to visualize the tumor, determine its size, location and spread, for planning surgical intervention.
- Spinal puncture and examination of cerebrospinal fluid for malignant cells presence.
- Biopsy and pathohistological examination of tissue samples. Only after a biopsy can the degree of malignancy and the specific subtype of astrocytoma be determined, on which treatment program will depend.
All materials after a biopsy of our patients are sent for revision to the best pathohistological laboratories in Israel, where they are reviewed by a qualified specialist in astrocytomas. Thanks to such checks, we are absolutely sure of diagnosis correctness and further chosen treatment tactics. Also, after a biopsy, we can perform innovative molecular genetic tests to identify some features of tumor cells, which allow us to select the most effective treatment regimen, as well as modern immunotherapy drugs.
Prognosis for astrocytoma in a child
The vast majority of astrocytomas that are diagnosed in children are characterized by a low degree of malignancy and have a favorable prognosis with a 5-year survival rate of 95%. In case of high-grade astrocytomas, 5-year survival rate is only 10-30%. The prognosis for astrocytoma is influenced by several factors:
- Type and malignancy degree of astrocytoma.
- Localization of tumor in central nervous system.
- Possibility of complete surgical tumor removal.
- Age of child at the time of diagnosis.
- Tumor spread to healthy areas of brain.
- The child has a genetic disease, for example, neurofibromatosis type 1.
- Molecular genetic features of tumor cells.
- The tumor is primary or the doctor is dealing with a relapse.
Astrocytoma modern treatment in children
Children with brain tumors, including astrocytomas, should be treated only by doctors from clinics where there is a specialized department of pediatric oncology and neurosurgery. Tel Aviv Medical Clinic is just such a medical center. We employ highly qualified specialists who are proficient in modern comprehensive treatment programs. The goal of any therapy program is to treat child as sparingly as possible and at the same time reduce the risks of possible side complications during treatment and long-term consequences after its completion.
Surgery to tumor removal is the main treatment for astrocytoma, regardless of its type. For tumors of the first malignancy degree, only surgical intervention may be sufficient to completely cure patients. Its goal is the most complete resection of tumor conglomerate. However, this is not always possible due to risk of damage to delicate nerve structures of brain or spinal cord. And in some cases, surgery is completely impossible due to tumor location (deep location, for example, in brain stem).
Stereotactic radiosurgery is used in children for benign tumors (pilocytic astrocytoma). If necessary, surgery is performed using a gamma knife under MRI guidance.
Chemotherapy is often used in addition to surgery or as primary treatment when surgery is not possible. Chemotherapy protocol depends on factors such as disease extent and molecular characteristics of tumor. Chemotherapy used in cases of low-grade astrocytoma includes application of such drugs as: vincristine and carboplatin, vinblastine, thioguanine, lomustine, procarbazine.
Other chemotherapy protocols may be used, especially in clinical trials. However, only chemotherapy usually does not lead to a complete cure for astrocytoma. If tumor is not removed surgically, it can develop into a long-term or chronic condition.
Targeted therapy are drugs that specifically affect specific targets in tumor cells. Targeted drugs are currently used primarily to treat low-grade tumors (juvenile pilocytic astrocytoma).
The target in malignant cells in such situations is changes in BRAF gene, which helps to control the function of a protein important for the growth and reproduction of tumor cells. Treating patients with a tumor characterized by a BRAF V600 gene mutation, BRAF inhibitor drugs (vemurafenib, dobrofenib) are used. MEK inhibitors (selumetinib, trametinib) may also be used. In some patients, mTOR inhibitors – everolimus, sirolimus – may be effective.
Immunotherapy is a method of astrocytoma treating using the patient’s own immune system, which recognizes tumor cells and attacks them after a certain “modification” and training. Examples of immunotherapy drugs being investigated for astrocytoma treatment are checkpoint inhibitors. These drugs help to block signals from cancer cells that protect them from attack by patient’s immune system.
Hematopoietic stem cell transplantation (bone marrow transplantation) with high-dose chemotherapy can be used in complex treatment of patients with high-grade astrocytomas. After a course of high-dose chemotherapy, which is necessary to destroy cancer cells, patient undergoes an autologous bone marrow transplantation (his own hematopoietic stem cells, which were harvested before the start of high-dose polychemotherapy course).
