This is a prospective randomized clinical trial, to determine whether dose-intensive tandem Consolidation, in a randomized comparison with single cycle Consolidation, provides an event-free survival (EFS) and overall survival (OS). The study population will be high-risk patients (non-Wnt and non-Shh sub-groups) with medulloblastoma, and for all patients with central nervous system (CNS) embryonal tumors completing "Head Start 4" Induction. This study will further determine whether the additional labor intensity (duration of hospitalizations and short-term and long-term morbidities) associated with the tandem treatment is justified by the improvement in outcome. It is expected that the tandem (3 cycles) Consolidation regimen will produce a superior outcome compared to the single cycle Consolidation, given the substantially higher dose intensity of the tandem regimen, without significant addition of either short-term or long-term morbidities.
HeadStart4: Newly Diagnosed Children (<10 y/o) With Medulloblastoma and Other CNS Embryonal Tumors Clinical and Molecular Risk-Tailored Intensive and Compressed Induction Chemotherapy Followed by Consolidation With Randomization to Either Single Cycle or to Three Tandem Cycles of Marrow-Ablative Chemotherapy With Autologous Hematopoietic Progenitor Cell Rescue
Due to the inferior response and event-free survival data of Regimens D and D2 on "Head Start III" for all children with supratentorial embryonal tumors, in comparison with the published data from "Head Start II" with Regimen A2 for metastatic patients, all such patients will receive the "Head Start II" Induction Regimen A2, on "Head Start 4", for either three or five cycles, depending upon whether or not they achieve complete remission by the end of Induction cycle #3. They will then undergo randomization to either single cycle or three tandem cycles of Consolidation marrow-ablative chemotherapy with AuHPCR.
Because of the unsatisfactory event-free survival for young children with non-desmoplastic/extensive nodular medulloblastoma (predominantly non-Shh and non-Wnt medulloblastoma subgroups) on Regimens D and D2 of "Head Start III", all these patients will receive the "Head Start II" Induction Regimen A2 on ""Head Start 4"", for either three or five cycles, depending upon whether or not they achieve complete remission by the end of Induction cycle #3. They will then undergo randomization to either single cycle or three tandem cycles of Consolidation marrow-ablative chemotherapy with AuHPCR.
Because of the excellent event-free and overall survival for young children with good risk medullo-blastoma (Shh or Wnt subgroups) treated with up-front "Head Start" chemotherapy strategies, such patients will undergo risk-tailored reduction of duration of Induction therapy from five cycles to three cycles of the "Head Start II" Induction Regimen A2 on "Head Start 4" for patients achieving a complete response to 3 cycles, followed, provided they are also without evidence of residual tumor following recovery from Induction cycle #3. They will NOT then undergo randomization, but will follow with a single cycle of Consolidation marrow-ablative chemotherapy as in "Head Start" studies.