Childhood medulloblastoma.

Among all the childhood central nervous system tumours, medulloblastoma and other neuroectodermal tumours account for 16-25% of cases. The causative factors of medulloblastoma/PNET have not been well established. It is more frequent in boys than in girl and in children than in adults. There was a significant improvement of survival for children diagnosed in 2000-2002 compared to those diagnosed in 1995-1999. The risk of dying was reduced by 30%. Patients are generally divided into risk-stratified schemes on the basis of age, the extent of residual disease, and dissemination. Sixty to 70% of patients older than 3 years are assigned to the average-risk group. High-risk patients include those in the disseminated category, and in North American trials those that have less than a gross or near-total resection, which is arbitrarily defined as 1.5 cm(2) of post-operative residual disease. Current and currently planned clinical trials will:define molecular and biological markers that improve outcome prediction in patients with medulloblastoma and which can be incorporated for front-line stratification of newly defined risk subgroups.