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Information from PDQ -- for Health Professionals
Childhood cerebellar astrocytoma
208/00289
** GENERAL INFORMATION **
This treatment information summary on childhood cerebellar astrocytoma 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
are increasingly 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:
1. cerebellar astrocytoma (usually pilocytic but also fibrillary and
high-grade)
2. medulloblastoma (primitive neuroectodermal tumor)
3. ependymoma (low-grade or anaplastic)
4. brain stem glioma (often diagnosed neuroradiographically without biopsy;
may be high-grade or low-grade)
5. atypical teratoid
Supratentorial tumors include those tumors that occur in the sellar or
suprasellar region and/or other areas of the cerebrum. Sellar/suprasellar
tumors comprise approximately 20% of childhood brain tumors and include the
following:
1. craniopharyngioma
2. diencephalic (chiasm, hypothalamic, and/or thalamic) gliomas generally of
low grade
3. germ cell tumors (germinoma and nongerminomatous)
Other tumors that occur supratentorially include the following:
1. low-grade astrocytoma or glioma (grade 1 or grade 2)
2. high-grade or malignant astrocytoma (anaplastic astrocytoma, glioblastomas
multiforme (grade 3 or grade 4))
3. mixed glioma (low-grade or high-grade)
4. oligodendroglioma (low-grade or high-grade)
5. primitive neuroectodermal tumor (cerebral neuroblastoma)
6. ependymoma (low-grade or anaplastic)
7. meningioma
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)
11. metastasis (rare) from extra neural malignancies
Important general concepts that should be understood by those caring for a
child who has a brain tumor include the following:
1. Selection of an appropriate therapy can only occur if the correct diagnosis
is made and the stage of the disease is accurately determined.
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 before 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.
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.[4]
6. The cause of the vast majority of childhood brain tumors remains
unknown.[5,6]
This summary discusses the treatment of childhood cerebellar astrocytoma.
Information about ongoing clinical trials is available from the NCI
(http://cancer.gov/clinical_trials/).
References:
1. Heideman RL, Packer RJ, Albright LA, et al.: Tumors of the central
nervous system. In: Pizzo PA, Poplack DG, eds.: Principles and Practice
of Pediatric Oncology. Philadelphia, Pa: Lippincott-Raven, 3rd ed.,
1997, pp 633-697.
2. Pollack IF: Brain tumors in children. New England Journal of Medicine
331(22): 1500-1507, 1994.
3. Cohen ME, Duffman PK, eds: Brain Tumors in Children: Principles of
Diagnosis and Treatment, 2nd ed. New York: Raven Press, 1994.
4. Sanders J, Glader B, Cairo M, et al.: Guidelines for the pediatric cancer
center and role of such centers in diagnosis and treatment. American
Academy of Pediatrics Section Statement Section on Hematology/Oncology.
Pediatrics 99(1): 139-141, 1997.
5. Kuijten RR, Bunin GR: Risk factors for childhood brain tumors. Cancer
Epidemiology, Biomarkers and Prevention 2(3): 277-288, 1993.
6. Kuijten RR, Strom SS, Rorke LB, et al.: Family history of cancer and
seizures in young children with brain tumors: a report from the
Childrens Cancer Group (United States and Canada). Cancer Causes and
Control 4(5): 455-464, 1993.
** CELLULAR CLASSIFICATION **
The classification of brain tumors is based on both histopathologic
characteristics and location in the brain. More than 80% of all childhood
cerebellar gliomas will be pilocytic astrocytomas, which are also considered to
be grade 1 astrocytomas. The majority of the remainder will be diffuse or
fibrillary astrocytomas. Malignant gliomas are rare.[1] The pathologic
classification of pediatric brain tumors is a specialized area that is
undergoing evolution; review of the diagnostic tissue by a neuropathologist who
has particular expertise in this area is strongly recommended.
These generally low-grade, often cystic astrocytic tumors are localized to the
cerebellum. Except for malignant gliomas, contiguous spread or metastasis
outside that region is extremely rare. The presence of certain histologic
features has been used retrospectively to stratify cerebellar astrocytomas into
two distinct groups: pilocytic or Gilles type A tumors and diffuse or Gilles
type B tumors; the latter tumors have a poor prognosis. Expert neuropathologic
review is important.
References:
1. Kleihues P, Cavenee WK, eds.: Pathology and Genetics of Tumours of the
Nervous System. Lyon, France: International Agency for Research on
Cancer, 2000.
** STAGE INFORMATION **
For information on the histologic features of cerebellar astrocytoma, refer to
the cellular classification section of this summary. There is no accepted
staging for childhood cerebellar astrocytomas.
** TREATMENT OPTION OVERVIEW **
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.
The designations in PDQ that treatments are "standard" or "under clinical
evaluation" are not to be used as a basis for reimbursement determinations.
** UNTREATED CHILDHOOD CEREBELLAR ASTROCYTOMA **
Surgical resection is the primary treatment for childhood cerebellar
astrocytoma.[1,2] Complete or near complete removal can be obtained in 90% to
95% of patients with juvenile pilocytic tumors. Diffuse cerebellar
astrocytomas may be less amenable to total resection, and this may account for
the poorer outcome. The extent of resection necessary for cure is unknown
because patients with microscopic and even gross residual tumor after surgery
may experience long-term progression-free survival without postoperative
therapy. Following resection, a post-operative MRI is obtained. Surveillance
scans are then obtained periodically for 5 years for totally resected tumors,
although the value of this is uncertain.[3] The optimal use of radiation
therapy is the subject of controversy. Some radiation oncologists advocate the
treatment of patients with residual disease, and others withhold treatment
until tumor progression has been documented. Chemotherapy may be useful for
delaying radiation therapy in the very young child with unresectable,
progressive cerebellar astrocytoma.[4]
References:
1. Campbell JW, Pollack IF: Cerebellar astrocytomas in children. Journal of
Neuro-Oncology 28(2-3): 223-231, 1996.
2. Schneider JH Jr, Raffel C, McComb JG: Benign cerebellar astrocytomas of
childhood. Neurosurgery 30(1): 58-62; discussion 62-63, 1992.
3. Sutton LN, Cnaan A, Klatt L, et al.: Postoperative surveillance imaging
in children with cerebellar astrocytomas. Journal of Neurosurgery
84(5): 721-725, 1996.
4. Packer RJ, Lange B, Ater J, et al.: Carboplatin and vincristine for
recurrent and newly diagnosed low-grade gliomas of childhood. Journal
of Clinical Oncology 11(5): 850-856, 1993.
** RECURRENT CHILDHOOD CEREBELLAR ASTROCYTOMA **
Recurrence may take place in childhood cerebellar gliomas and may develop many
years after initial treatment. Disease can be 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 to determine the extent of relapse is indicated for all patients .
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 with cerebellar astrocytoma (pilocytic or diffuse) who relapse after
being treated with surgery alone should be considered for another surgical
resection.[1] If this is not feasible, local radiation therapy is the usual
treatment. If there is recurrence in an unresectable site after irradiation,
chemotherapy should be considered.[2] There is little information regarding
the activity of chemotherapy in this disease. Studies of novel therapeutic
approaches that are designed to test the activity and toxicity of chemotherapy
in recurrent brain tumor patients should be considered.
References:
1. Austin EJ, Alvord EC: Recurrences of cerebellar astrocytomas: a violation
of Collins' law. Journal of Neurosurgery 68(1): 41-47, 1988.
2. Packer RJ, Lange B, Ater J, et al.: Carboplatin and vincristine for
recurrent and newly diagnosed low-grade gliomas of childhood. Journal
of Clinical Oncology 11(5): 850-856, 1993.
Date Last Modified: 06/2002
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This information has been brought to you by
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