Outcome for children ≤3 years of age with malignant brain or spinal cord tumors treated with high dose chemotherapy with peripheral blood stem cell rescue.

8552 Background: Children ≤3 years of age (yo) with malignant brain tumors have a dismal prognosis. In a POG study starting in 1986 (NEJM Jun '93), 102 patients had a 1 and 2 year progression free survival (PFS) of 41% and 39% respectively after chemotherapy using repetitive 28 day cycles of cyclophosphamide plus vincristine, followed by cisplatin plus etoposide. In an attempt to delay or obviate radiation therapy and improve outcome, our institution has treated children ≤3 yo with newly diagnosed malignant brain tumors with high dose chemotherapy (HDC) followed by peripheral blood stem cell (PBSC) rescue.,Since August 1998, 14 children (age 4-38 mos) with malignant brain and spinal cord tumors have been treated at our institution. All patients received 3 cycles of induction chemotherapy (cisplatin 3.5 m/kg -day 0, cyclophosphamide 60 mg/kg -day 1 and 2, etoposide 2.5 mg/kg -day 0 to 2, vincristine 0.05 mg/kg, day 0, 7, 14) followed by 3 cycles of HDC (carboplatin 17 mg/kg and thiotepa 6mg/kg day 0 and 1) with PBSC rescue after each cycle. Histology included 9 medulloblastoma/PNET (6 post. fossa/brainstem, 3 supratentorial; 7 M0, 1 M1 and 1 M3), 4 malignant glioma (2 supratentorial, 2 brainstem; 3 M0, 1 M3) and 1 ependymoma. Outcome and treatment toxicities were evaluated by retrospective chart review.,3 of 14 children are currently undergoing HDC and are too early to be evaluable. 1 and 2 year PFS for the remaining 11 is 81% and 63%. 3 patients had disease progression (all M0 disease) at 8, 12, and 17 mos; 2 had received post-HDC radiation. 8 patients are alive and disease free 8 to 70 mos after completion of HDC (median 33 months). 5 of the 8 disease free patients had radiation therapy. Toxicity was primarily myelosuppression, with a total of 68 admissions for fever and neutropenia with G+ bacteremia detected in 32% of those admissions. There were no toxic deaths.,We are encouraged by the outcome of these 14 children ≤3 years of age with malignant brain tumors treated with HDC and PBSC rescue at our institution. The treatment regimen is well tolerated. The high incidence of gram+ bacteremia supports the use of broad-spectrum antimicrobial coverage for fever/neutropenia. No significant financial relationships to disclose.