TREATMENT RESULTS OF CHILDREN WITH HIGH RISK MEDULOBLASTOMA. A SINGLE CENTER EXPERIENCE

Objectives: The authors present the results of treatment strategies of children with high-risk meduloblastoma. The impact of early diagnosis, the radicalism of surgery and the treatment with the SJMB 3/97 protocol are evaluated.

Methods: Between 1999 and 2004, 11 boys and 6 girls were treated. Mean age at the time of diagnosis was 9 years (range 3.3–18.0). The main clinical features are intracranial hypertension (10), cerebellar symptoms (5) and cranial nerves symptoms (2). MRI of the brain showed a tumor in fourth ventricle (13), in cerebellar hemisfere (2) and in supratentorial area (2). Two children had dissemination at the time of diagnosis. Complete tumor resection was performed in 10 patients, subtotal resection of the tumor (residual tumor greater than 1.5cm] was performed in 7 patients. The following prognostic markers were found: amplification of c-myc oncogene (10), amplification of N-myc oncogene (3), other cytogenetic abnormalities (6). After surgery, all children were irradiated on the craniospinal axis with boost on the primary tumor with concomitant vincristine, later they were treated with submyeloablative chemotherapy with periferal blood stem cell rescue.

Results: After radiotherapy 12 patients were in complete remission,4 patients were in partial remission, 1 patient had disease progression. After chemotherapy 13 patients were in complete remission,2 patients were in partial remission, 1 patient had disease progresion and 1 patient died. Hematotoxicity and gastrointestinal toxicity were found in all patients, neurotoxicity was found in 8 patients. Over all survival and event free survival is 82.4%.

Conclusion: The crucial positive prognosis factors in children with high risk meduloblastoma are complete resection of the tumor, no evidence of leptomeningeal disease and no evidence of amplification of c-myc oncogene. Initial evaluation shows feasibility of this regimen in the treatment of high-risk brain tumors with promising results, despite a high but manageable toxicity.