PDQ® Treatment Health Professionals
This treatment information summary on childhood cerebral astrocytomas is an overview of diagnosis, classification, patient treatment, and prognosis. The National Cancer Institute created the PDQ database to increase the availability of new treatment information and its use in treating patients. Information and references from the most recently published literature are included after review by pediatric oncology specialists.
Primary brain tumors are a diverse group of diseases that together constitute the most common solid tumor of childhood. Brain tumors are classified according to histology, but tumor location and extent of spread are important factors that affect treatment and prognosis. Immunohistochemical analysis, cytogenetic and molecular genetic findings, and measures of mitotic activity have been used in tumor diagnosis and classification.
Approximately 50% of brain tumors in children are infratentorial, with three fourths of these located in the cerebellum or fourth ventricle. Common infratentorial (posterior fossa) tumors include the following:
2. medulloblastoma (primitive neuroectodermal tumor)
4. brain stem glioma (often diagnosed neuroradiographically without biopsy; may be high- or low-grade)
2. diencephalic (chiasm, hypothalamic, and/or thalamic) gliomas generally of low grade
2. high-grade or malignant astrocytoma (anaplastic astrocytoma, glioblastoma multiforme (grade 3 or grade 4))
3. mixed glioma
5. primitive neuroectodermal tumor (cerebral neuroblastoma)
8. choroid plexus tumors (papilloma and carcinoma)
9. pineal parenchymal tumors (pineoblastoma, pineocytoma, or mixed pineal parenchymal tumor)
10. neuronal and mixed neuronal glial tumor (ganglioglioma, desmoplastic infantile ganglioglioma, dysembryoplastic neuroepithelial tumor)
2. Children with primary brain tumors represent a major therapy challenge that, for optimal results, requires the coordinated efforts of pediatric specialists in fields such as neurosurgery, neurology, rehabilitation, neuropathology, radiation oncology, medical oncology, neuroradiology, endocrinology, and psychology, who have special expertise in the care of patients with these diseases.[1-3]
3. More than one half of children diagnosed with brain tumors will survive 5 years from diagnosis. In some subgroups of patients, an even higher rate of survival and cure is possible. Each child's treatment should be approached with curative intent, and the possible long-term sequelae of the disease and its treatment should be considered when therapy is begun.
4. For the majority of childhood brain tumors, the optimal treatment regimen has not been determined. Children who have brain tumors should be considered for enrollment in a clinical trial when an appropriate study is available. Such clinical trials are being carried out by institutions and cooperative groups. In the United States, the two major cooperative groups are the Pediatric Oncology Group and the Childrens Cancer Group.
5. Guidelines for pediatric cancer centers and their role in the treatment of pediatric patients with cancer have been outlined by the American Academy of Pediatrics.
For information on current clinical trials for children with brain tumors, consult the PDQ Protocol File.
Various classification schemata have been used to separate glial tumors into prognostic subsets. According to the most recent classification of the World Health Organization, glial tumors are divided on the basis of histologic criteria into the following subsets: pilocytic astrocytomas, low-grade nonpilocytic astrocytomas, anaplastic gliomas, and glioblastomas multiforme. Various types of nonpilocytic astrocytomas, such as fibrillary protoplasmic and gemistiocytic, have been identified. Both malignant and benign varieties of oligodendrogliomas may occur. In young children, new variants such as dysembryoplastic neuroepithelial tumor and desmoplastic infantile gangliogliomas are increasingly recognized. Mixed gliomas are classified separately, as are gangliogliomas and other primary neuronal tumors. In general, the grade of the tumor is predictive of outcome; patients with higher grade tumors have a poorer prognosis. Other parameters, such as mitotic index evaluators, that may be independently predictive of outcome (especially in low-grade tumors) may not yet have been incorporated into the classification schema.
Low-grade cerebral astrocytomas (pilocytic and fibrillary) have a relatively favorable prognosis, particularly if complete excision is possible.[1,2] There is no generally recognized staging system. Tumor spread is usually by contiguous extension; dissemination to other central nervous system sites may rarely occur. Although metastasis is unlikely, tumors may be of multifocal origin, especially when associated with neurofibromatosis.
High-grade or malignant astrocytoma (anaplastic astrocytoma, glioblastoma multiforme) may occur anywhere above the tentorium. Malignant astrocytoma is often locally invasive and extensive.[1,2] Spread via the subarachnoid space may occur. Metastasis outside of the central nervous system has been reported but is extremely rare. There is no generally recognized staging system. Although malignant astrocytoma carries a generally poor prognosis in younger patients, those with anaplastic astrocytoma disease and those in whom a gross total resection is possible may fare better.
Many of the improvements in survival in childhood cancer have been made as a result of clinical trials that have attempted to improve on the best available, accepted therapy. Clinical trials in pediatrics are designed to compare new therapy with therapy that is currently accepted as standard. This comparison may be done in a randomized study of two treatment arms or by evaluating a single new treatment and comparing the results with those that were previously obtained with existing therapy.
Because of the relative rarity of cancer in children, all patients with brain tumors should be considered for entry into a clinical trial. To determine and implement optimum treatment, treatment planning by a multidisciplinary team of cancer specialists who have experience treating childhood brain tumors is required. Radiation therapy of pediatric brain tumors is technically very demanding and should be carried out in centers that have experience in that area in order to ensure optimal results.
Debilitating effects on growth and neurologic development have frequently been observed following radiation therapy, especially in younger children.[1-3] For this reason, the role of chemotherapy in allowing a delay in the administration of radiation therapy is under study, and preliminary results suggest that chemotherapy can be used to delay, and sometimes obviate, the need for radiation therapy in children with benign and malignant lesions. Long-term management of these patients is complex and requires a multidisciplinary approach.
The designations in PDQ that treatments are "standard" or "under clinical evaluation" are not to be used as a basis for reimbursement determinations.
The usual treatment for low-grade supratentorial astrocytoma is surgery. There is no evidence that radiation therapy is of benefit for patients with completely resected tumors. For patients with incompletely resected tumor, treatment options include observation, re-resection, radiation, and/or chemotherapy and must be individualized. Radiation therapy is often reserved until progressive disease is documented.[1,2] Radiation fields encompass the tumor, and doses of 5,400 cGy are common. Evaluation with detailed electroencephalographic mapping and surgery designed to remove the tumor and adjacent epileptic foci has been recommended for those patients with low-grade tumor and seizures.[3,4] However, excellent results in tumor and seizure control have been reported with magnetic resonance-based "total" tumor resection. Low-grade tumors may respond to various chemotherapeutic regimens, including carboplatin. Chemotherapy may delay the need for radiation therapy; its role in the treatment of children younger than 5 years of age with newly diagnosed, progressive lesions is under study.
The therapy for both children and adults with supratentorial high-grade astrocytoma includes surgery, radiation therapy, and chemotherapy. Outcome in high-grade gliomas occurring in childhood may be more favorable than that in adults, but it is not clear if this difference is caused by biologic variations in tumor characteristics, therapies used, tumor resectability, or other factors that are not presently understood. The ability to obtain a complete resection is associated with a better prognosis. Radiation therapy is administered to a field that widely encompasses the entire tumor. Alternatively, it can be administered to the entire brain with a "cone down" to the tumor volume. The radiation therapy dose is usually at least 5,400 cGy. Chemotherapy with a nitrosourea has been demonstrated to prolong survival in adults by approximately 3 months. Chemotherapy may also be useful in children with this disease. A more notable result was seen in children with glioblastoma multiforme who were treated on one prospective, randomized trial with adjuvant lomustine, vincristine, and prednisone. The use of more aggressive drug regimens is under study but has not yet been shown to improve survival. In children with recurrent high-grade gliomas, one study has reported encouraging disease control in those with minimal bulk disease at the time of initiation of chemotherapy. Children younger than 3 years of age may benefit from chemotherapy to delay, modify, or, in selected cases, obviate the need for radiation therapy.[6,7] Clinical trials that evaluate chemotherapy with or without radiation therapy are ongoing. Consult the PDQ Protocol File for a listing of current trials.
Recurrence may take place in both benign and malignant childhood cerebral astrocytomas and may develop many years after initial treatment. Disease may recur at the primary tumor site or, especially in malignant tumors, at noncontiguous central nervous system sites. Systemic relapse is rare, but may occur. At the time of recurrence, a complete evaluation for extent of relapse is indicated for all malignant tumors and, at times, for more benign lesions. Biopsy or surgical resection may be necessary for confirmation of relapse because other entities, such as secondary tumor and treatment-related brain necrosis, may be clinically indistinguishable from tumor recurrence. The need for surgical intervention must be individualized on the basis of the initial tumor type, the length of time between initial treatment and the reappearance of the mass lesion, and the clinical status of the child.
Patients with recurrent cerebral astrocytoma after maximal surgery and irradiation may benefit from chemotherapy. They should be considered for entry into trials of novel therapeutic approaches. Drug combinations, such as carboplatin and vincristine, may be useful at the time of recurrence for children with low-grade gliomas.
Recurrence may occur in both benign and malignant childhood cerebral astrocytomas and may develop many years after initial treatment. Disease may recur at the primary tumor site or, especially in malignant tumors, at noncontiguous central nervous system sites. Systemic relapse is rare but may occur. At the time of recurrence, a complete evaluation for extent of relapse is indicated for all malignant tumors and, at times, for more benign lesions. Biopsy or surgical resection may be necessary for confirmation of relapse because other entities, such as secondary tumor and treatment-related brain necrosis, may be clinically indistinguishable from tumor recurrence. The need for surgical intervention must be individualized on the basis of the initial tumor type, the length of time between initial treatment and the reappearance of the mass lesion, and the clinical picture.
Patients for whom treatment fails may benefit from additional treatment, including high-dose chemotherapy with bone marrow rescue. They should be considered for entry into trials of novel therapeutic approaches.[3,4] Consult the PDQ protocol file for information on current clinical trials.
Date Last Modified: 08/1999