Medulloblastoma: present concepts of stratification into risk groups

For the past two decades, staging studies have been used to stratify children with medulloblastoma into risk groups. Therapeutic approaches have been based on separation of patients into 'average-risk' and 'poor-risk' categories. The extent of disease at diagnosis has been most reproducibly shown to be of prognostic significance, but age at diagnosis and amount of residual disease after surgery or extent of resection have also been commonly incorporated into stratification schemata. Tumor histology has been variably related to outcome. Biologic markers, especially molecular genetic findings, have not yet been incorporated into risk classifications, but will likely add to the understanding of medulloblastoma and may significantly alter concepts of staging and treatment.