Pediatric brain tumors

Neuropsychological functioning after surgery in children treated for brain tumor

OBJECTIVE

To describe the neuropsychological functioning of children treated with surgery only for localized brain tumors in Dana-Farber Cancer Institute Protocol 92-077. Subsequent reports will describe the neuropsychological functioning of children treated with surgery and stereotactic radiation therapy on Dana-Farber Cancer Institute 92-077.

METHODS

The intellectual functioning of 106 patients was evaluated within 3 months after surgery. An in-depth assessment of the neuropsychological functioning, including an impairment index, was conducted for a subset of 77 school-age children (6-16 yr old) across six functional domains. Descriptive statistics were generated; binomial distribution analyses were performed to assess whether the proportion of individuals with impaired performance on each measure exceeded normative expectations. The impairment index assessed whether poor performance was attributable to a few children or reflected the performance of the cohort as a whole.

RESULTS

Although the Full Scale IQ was within normative expectations, the Verbal IQ was higher than the Performance IQ with 45% of individuals showing a significant discrepancy (P < 0.01) between these scales. There was an increased prevalence of poor performance for measures of motor output, verbal memory, and visuospatial organization. The distribution of the impairment index indicated moderate impairment across the school-age cohort rather than severe impairment in a few patients.

CONCLUSION

The results document a moderate level of neuropsychological morbidity among children with brain tumors before stereotactic radiation therapy, presumably referable to the tumor itself and the surgery. The extent to which stereotactic radiation therapy may increase this burden will be assessed in follow-up studies evaluating the longitudinal neuropsychological data.

Innovative therapies for pediatric brain tumors

Success in the treatment of pediatric brain tumors has lagged behind that of other pediatric cancers. This paper highlights many of the advances that have taken place over the past few years in the surgical, radiotherapeutic, and chemotherapeutic approaches to central nervous system lesions that we hope will lead to a dramatic improvement in outcome. Innovations in neurosurgical and radiotherapeutic techniques have resulted in decreasing toxicity although substantial improvement in cure rates has not been observed. Many new techniques such as gene therapy, angiogenesis inhibitors, immunotherapy, and others that have not been part of the classic approach to these lesions are now in clinical trials in the hope that they will impact on the survival of these patients. The scientific basis for these new treatment modalities and preliminary clinical results are discussed.

Supratentorial pilocytic astrocytomas, astrocytomas, anaplastic astrocytomas and glioblastomas are characterized by a differential expression of S100 proteins

The levels of expression of the S100A1, S100A2, S100A3, S100A4, S100A5, S100A6 and S100B proteins were immunohistochemically assayed and quantitatively determined in a series of 95 astrocytic tumors including 26 World Health Organization (WHO) grade I (pilocytic astrocytomas), 23 WHO grade II (astrocytomas), 25 WHO grade III (anaplastic astrocytomas) and 21 WHO grade IV (glioblastomas) cases. The level of the immunohistochemical expression of the S100 proteins was quantitatively determined in the solid tumor tissue (tumor mass). In addition twenty blood vessel walls and their corresponding perivascular tumor astrocytes were also immunohistochemically assayed for 10 cases chosen at random from each of the four histopathological groups. The data showed modifications in the level of S100A3 protein expression; these modifications clearly identified the pilocytic astrocytomas from WHO grade II-IV astrocytic tumors as a distinct biological group. Modifications in the level of S100A6 protein expression enabled a clear distinction to be made between low (WHO grade I and II) and high (WHO grade III and IV) grade astrocytic tumors. Very significant modifications occurred in the level of S100A1 protein expression (and, to a lesser extent, in their of the S100A4 and S100B proteins) in relation to the increasing levels of malignancy. While the S100A5 protein was significantly expressed in all the astrocytic tumors (but without any significant modifications in the levels of malignancy), the S100A2 protein was never expressed in these tumors. These data thus indicate that several S100 proteins play major biological roles in human astrocytic tumors.