Current Therapy in Childhood Brain Tumors

Infratentorial ependymomas of childhood. Correlation between histological features, immunohistological phenotype, silver nucleolar organizer region staining values and post-operative survival in 16 cases

We have examined pathological criteria in 16 cases of infratentorial ependymomas of childhood using a conventional histological approach, with immunohistochemistry and silver nucleolar organizer region staining (AgNORs). We have found that some of these criteria are of prognostic value. The following histological features were evaluated in each case: cellular density, cellular or nuclear pleiomorphism, mitosis, focal necrosis, endothelial proliferation and complete loss of differentiation. The expression of the following antigens was also studied: epithelial membrane antigen (EMA), human natural killer (HNK1), glial fibrillary acidic protein (GFAP) and vimentin. Only three histological criteria have been retained as indicative of bad prognosis, i.e., high mitotic index, a large amount of necrosis and complete loss of differentiation. These criteria distinguish ependymomas from anaplastic ependymomas. GFAP was expressed in all tumors while other antigens were more variable. In addition tumors expressing large amounts of GFAP were statistically associated with a better prognosis. Increased vimentin expression associated with a decrease of GFAP immunoreactivity correlated with anaplasia and short survival. EMA was not directly correlated with postoperative survival but may be considered as a further prognostic factor. Finally AgNORs values were not statistically correlated with postoperative survival.

Brain tumors in children and adolescents--I. Effects on working, associative and serial-order memory of IQ, age at tumor onset and age of tumor

Memory impairment was demonstrated in a sample of 46 children and adolescents with brain tumors. The overall distribution of memory scores was skewed positively; over half of the total number of test measures were in the lowest quarter of the score distribution; and more than three-quarters of the individual subjects had at least one memory score in the impaired range. Verbal intelligence accounted for less than one-quarter of the variance in memory scores. The type of memory impairment was analyzed in relation to various demographic and medical variables: age at onset of tumor symptoms, age or duration of tumor, sex, pre-tumor developmental disturbances, pre-tumor closed head injury, post-tumor anticonvulsant treatment and post-tumor epileptic seizures. The working memory task, in which each in a succession of heard words is stored in temporary memory long enough to be compared to or contrasted with incoming words, was unaffected by these variables, as was memory for semantically-based word-picture associations. Memory for the serial order of pictures that corresponded to heard words varied inversely with the age at tumor onset such that the later the onset, the lower the memory test performance.

Infratentorial ependymomas in childhood: prognostic factors and treatment

The prognostic factors and survival data were analyzed for 35 children (aged under 16 years at diagnosis) with childhood infatentorial ependymomas treated surgically at The Hospital for Sick Children in Toronto during the years 1970 to 1987. Tumor histology was reviewed individually and grouped into three categories (Categories I to III) for survival analysis. An overall 5-year survival rate of 44.6% was obtained after the exclusion of perioperative mortality. Factors associated with an improved 5-year survival rate were: total tumor removal, noninvasive tumors, Category I histology, age greater than 6 years, and absent physical signs of parenchymal invasion or lower cranial nerve involvement. The 5-year survival rate was lower when associated with Category III histology, brain-stem or cranial nerve signs, age less than 2 years, tumor invasion and/or cranial nerve involvement, and subtotal tumor removal. Clinical evidence of spinal metastases was found to be uncommon (3.1%). Surgical excision followed by radiation therapy was the primary mode of treatment for these tumors. Different approaches regarding the volume of radiotherapy to be delivered and the use of adjuvant chemotherapy are discussed.