High-dose chemotherapy and autologous stem cell rescue in children with newly diagnosed high-risk or relapsed medulloblastoma or supratentorial primitive neuroectodermal tumor

Background. Single or tandem double high-dose chemotherapy (HDCT) was used to treat children with newly diagnosed high-risk or relapsed medulloblastoma and supratentorial primitive neuroectodermal tumor (MB/sPNET) in order to defer or avoid radiotherapy in young children. Procedure. Thirty-seven HDCTs were given to 25 children with newly diagnosed high-risk or relapsed MB/sPNET. Tandem double HDCT was used for 12 of 15 patients initially intended to receive double HDCT. Results. Three-year EFS (SE) in 6 newly diagnosed high-risk (> 3 years old), 8 newly diagnosed (< 3 years old), and 11 relapsed MB/sPNET was 83.3 +/- 15.2%, 62.5 +/- 20.5%, and 29.1 +/- 15.7%, respectively. Three-year EFS for patients in CR or PR and in less than PR at first HDCT was 67.4 +/- 11.0% and 16.7 +/- 15.2%, respectively (P=0.001). Three-year EFS inpatients initially intended to receive double HDCT and single HDCT was 66.0 +/- 12.4% and 40.0 +/- 15.5%, respectively. For 19 patients in CR or PR at first HDCT, 3-year EFS was 88.9 +/- 10.5% in tandem double HDCT group, and 44.4 +/- 16.6% in single HDCT group, respectively (P=0.037). Although four treatment-related mortalities (TRMs) occurred during 25 first HDCTs, no TRM occurred during 12 second HDCTs. In four of eight young children, craniospinal radiotherapy was successfully withheld without subsequent relapse. Conclusions. High-dose chemotherapy may improve the survival of children with newly diagnosed high-risk MB/sPNET, and, to some extent, the survival of those with relapsed MB/sPNET. Further study is necessary to elucidate the efficacy of tandem double HDCT. Pediatr Blood Cancer 2007;48:408-415. (c) 2006 Wiley-Liss, Inc.