MBCL-17. METASTATIC MEDULLOBLASTOMA CAN BE CURED WITHOUT EXCISION OF THE PRIMARY TUMOR: A SINGLE CENTER EXPERIENCE

INTRODUCTION: Metastatic medulloblastoma is a challenging disease The current clinical approach advocates removal of the primary tumor in the posterior fossa despite evidence of metastatic disease and administer oncologic treatment within several weeks: Infants of 3–4 years are treated by tandem high dose chemotherapy with stem cell support (ACNS0334 protocol), while older children are given radiotherapy and tandem high dose chemotherapy with stem cell support (SJMB03 protocol). We postulate that a resection of the primary tumor is not obligatory, and a biopsy may suffice in order to enable prompt oncological treatment without affecting the long-term survival. PATIENTS AND METHODS: Between 2010-2019 7 patients with metastatic medulloblastoma (median age 4.5, age 1–10) were treated with biopsy only, five spinal and two from the primary tumor. Six children had a concurrent VP shunt. Four presented with cord compression, and two with neurological deterioration. Four needed emergency radiotherapy. Two infants received protocol ACNS0334, five patients received protocol SJMB03. RESULTS: Six patients (85%) survived; .3 patients are long term survivors (> 5 years), 2 patients are in remission for 2–3 years, one patient is on active therapy. Only 1 patient died after a late (4 years) metastatic relapse not in the posterior fossa. CONCLUSIONS: Metastatic medulloblastoma can be cured without excision of the primary tumor and without mutilating surgery. Long term prognosis is probably more attributable to disease subtype and prompt oncologic treatment. This approach merits further studies and may have implications on treatment of non-metastatic tumors.