MBCL-32. HIGH-DOSE CHEMOTHERAPY WITH STEM CELL RESCUE FOR RECURRENT PREVIOUSLY IRRADIATED MEDULLOBLASTOMA

BACKGROUND/OBJECTIVES: Relapse of medulloblastoma (MB) is highly lethal in previously irradiated patients. As one of therapeutic options for recurrence MB, high-dose chemotherapy with stem cell rescue (HDSCR) is suggested. The aim of our work was to evaluate the effectiveness of this therapy. DESIGN/METHODS: We retrospectively analyzed the data of 8 pts with previously irradiated relapse MB using HDSCR. Initially, M0-stage was verified in 4 cases. Histological diagnoses were desmoplastic (2 pts), classic (2 pts), anaplastic (2 pts) and MB NOS (2 pts). Molecular genetic analyses was performed in 6 cases: Group 3 was verified in 2 cases (1-classic, 1-anaplastic), Group 4 – in 3 cases (1-classic, 1-anaplastic, 1-desmoplastic). Time to first PD was from 15 to 86 months (median=29,4 months). Local relapse was revealed in 1 pt, metastatic – in 5 pts, mixed – in 2 pts. RESULTS: All pts were treated according HIT-REZ 2005 (3–5 cycles without/with intraventricular etoposide), with CR achieved in 3 pts and PR in 5 pts. HDCT regimens consisted of carboplatin, etoposide, thiotepa and temozolomide. 2 pts received re-irradiation – focal RT (1) and CSI (1). 7/8 patients died, 1 pt alive with PD. Time from HDCT to death was 5–15 months (median=9,6 months). CONCLUSIONS: HDSCR for recurrent previously irradiated MB is ineffective. Use of other methods should be considered in these cases.