Benign cerebellar astrocytomas in children

Cerebellar astrocytomas are benign tumors of childhood known to be associated with excellent long-term survival in patients in whom complete surgical resection is possible. However, the roles of other factors--clinical, radiological, histological, and therapeutic--in the survival of the patient, tumor recurrence, and long-term patient outcome remain imprecise. The goal of this study was to examine these factors and their relationships.

To clarify these issues a retrospective review was conducted of 168 children who were surgically treated for a cerebellar astrocytoma at Hôpital Necker-Enfants Malades between 1955 and 1995. These patients' clinical files were examined, the histological characteristics of their tumors were reviewed, and their outcomes were assessed according to Bloom's scale and the Wechsler intelligence quotient test. Of the 168 patients in the study, 91 were male and 77 were female with a mean age of 6.9 years and a mean follow up lasting 7.7 years. Tumors were identified as being strictly located in the cerebellum in 76.2% of the patients and as involving the brainstem (referred to as the "transitional form") in 23.8% of the patients. Complete surgical excision was possible in 88.7% of cases. There was a total mortality rate of 4.2% and a tumor recurrence rate of 9.5%. Fifty-eight percent of the patients had no neurological sequelae at follow-up evaluation. Pejorative factors that were discovered by multivariate analysis to be important included: a long preoperative duration of symptoms and the transitional form of tumor with respect to survival; incomplete tumor excision with respect to an increased risk of recurrence; and a long preoperative duration of symptoms, an early epoch during which surgery was performed (1955-1974), severe ventricular dilation, and the transitional form of tumor with respect to a poorer long-term patient outcome.

The presence of brainstem involvement (tumor in the transitional form) emerged as a significant negative prognostic factor and should be treated as a distinct nosological entity. The extent of surgical excision has a significant bearing on the risk of tumor recurrence.