Affiliations: Neuro-Oncology Program, Division of Oncology,
University Children's Hospital of Zurich, Switzerland
Note: [] Correspondence: PD Dr., Michael A. Grotzer, University
Children's Hospital Steinwiesstrasse 75 8032 Zurich, Switzerland. Tel: +411 266
71 11; fax: + 411 266 71 71; E-mail: Michael.Grotzer@kispi.unizh.ch
Abstract: Central nervous system primitive neuroectodermal tumors (PNET)
including cerebellar PNET (medulloblastoma, PNET/MB) are the most common
malignant brain tumors in childhood. Because of the high risk of leptomeningeal
dissemination, standard postoperative treatment for PNET includes craniospinal
radiotherapy and chemotherapy. Such treatment causes long-term morbidity
including endocrine and growth disturbances, as well as neurocognitive
dysfunction, which is particularly severe in young children. Over the last
years, neurotrophin receptor TrkC, neuregulin receptor ErbB2 and oncogene MYC
have been identified as biological prognostic factors in PNET/MB. High TrkC
mRNA expression, low ErbB2 protein expression and low MYC mRNA expression are
powerful independent predictors of favorable clinical outcome in PNET/MB. Upon
validation in ongoing prospective biological studies, these biological factors
may define risk groups and help direct therapy decisions for children with
PNET/MB. In PNET with favorable biological factors and no evidence of
leptomeningeal tumor dissemination, therapy with reduced craniospinal radiation
might retain the efficacy but reduce the toxicity and therefore improve the
quality of life for the survivors. (J Pediatr Neurol 2003; 1(2): 75–82).
