Outcome for children <4 years of age with malignant central nervous system tumors treated with high-dose chemotherapy and autologous stem cell rescue

Background. Children < 4 years of age (yo) with malignant central nervous system (CNS) tumors have a dismal prognosis. In an attempt to delay or obviate radiation therapy (XRT) and improve outcome, our institution has treated children < 4 yo with newly diagnosed malignant CNS tumors with high-dose chernotherapy (HDC) and autologous stem cell rescue (ASCR) followed by selective XRT. Procedure. Fifteen children (age 4-38 months) with malignant CNS tumors have completed treatment with HDC/ASCR. All patients received three cycles of induction chemotherapy (cisplatin 3.5 mg/ kg- day 0, cyclophosphamide 60 mg/kg- day 1 and 2, etoposide 2.5 mg/kg- day 0-2, vincristine 0.05 mg/kg, day 0, 7, 14) followed by three cycles of HDC (carboplatin 17 mg/kg and thiotepa 6 mg/kg, day 0 and 1) with ASCR. Histology included five medulloblastomas, four primitive neuroectodermal turnors (PNET), five malignant gliomas, and one epenclymoma. Outcome and treatment toxicities were evaluated by retrospective chart review. Results. Median follow-up time of the 15 patients is 22 months (range 8-82 months). The 1- and 2-year progression-free survival (PFS) is 86.1 % and 52.2% and overall survival (OS) 91.6% and 72.1%, respectively. Ten patients are alive and disease free 3-77 months (median 18 months) after having completed HDC/ASCR, there off five received XRT. Toxicity was primarily myelosuppression. There was no treatment mortality. Conclusions. We are encouraged by the outcome of 15 children < 4 yo with malignant CNS tumors treated with tandem cycles of HDC and ASCR. The treatment regimen is relatively well tolerated.