High-resolution, genome-wide analysis of human medulloblastoma samples by array-Comparative Genomic Hybridization (aCGH)

Medulloblastoma (MB) is the most common pediatric brain tumor and is an aggressive neoplasia arising in the cerebellum. MB includes four major histological subsets commonly subdivided in: classic, desmoplastic, anaplastic or large-cell, and nodular. The current patients risk stratification is based on the age at diagnosis (> or < 3 years at diagnosis), the extent of residual tumor mass post-operative, and disease dissemination. An average risk is assigned to patients older than 3 years of age with minimal or no tumor residual. These patients are more than 60% of overall MBs and have an overall survival between 50-70% at 5 years. It is widely accepted that tumor aggressiveness and progression depend on genetic abnormalities. We performed the genome-wide study, focused on classic MB belonging to pediatric patients at standard risk. We analyzed 31 MB samples using high resolution oligonucleotide Human Genome CGH 244K (Agilent Technologies). The present study may help to identify novel molecular prognostic markers useful to refining current criteria of patients´ relapse risk estimation in this subgroup of patients. We analyzed 31 samples of classic medulloblastoma from patients older than 3 years of age at diagnosis