CNS-85 TRIAL - A COOPERATIVE PEDIATRIC CNS TUMOR STUDY - RESULTS OF TREATMENT OF MEDULLOBLASTOMA PATIENTS

Between 1985 and 1989, 38 children with newly diagnosed medulloblastom a entered our therapeutic protocol. After surgery and postoperative st aging assessments, patients were assigned to risk groups. Eleven with ''standard-risk'' (SR) tumors were treated with radiation therapy alon e, while 27 with ''high-risk'' (HR) tumors received radiation therapy plus adjuvant chemotherapy with vincristine, methotrexate, VM-26, and 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU). After a minimum f ollow-up of 5 years (range 5-9 years) 21/38 children had developed a r ecurrence or progression of their disease and 19/38 patients had died. Five-year event-free survival rates and 5-year total survival rates f or all 38 patients were 47.4% and 50% respectively. The event-free sur vival rates at 5 years for SR and HR patients separately were 27.3% an d 55.6%, respectively. The corresponding 5-year total survival rates w ere 27.3% and 59.3%. The differences were not statistically significan t. Univariate analysis showed age at diagnosis to be the most importan t prognostic factor. Infants aged 5 years or less had a significantly shorter event-free survival time than older patients (P=0.00897). Simi lar effects were found when total survival time was considered. There were significant differences in outcome in patients receiving differen t doses of radiation, suggesting a dose-response relationship. A Cox s tepwise multivariate analysis showed age at diagnosis as the only inde pendent prognostic factor. Variables relating to treatment entered the model, suggesting that chemotherapy could play an important role in d etermining outcome.