Myeloablative combination chemotherapy without total body irradiation for neuroblastoma

Myeloablative treatment intensification in 25 patients diagnosed when older than 12 months of age with stage IV neuroblastoma included sequential delivery of cisplatin 120 mg/m2 x 1, hyperfractionated radiation (2,100 cGy) to the primary site and adjacent lymph nodes, carmustine (BCNU) 200 mg/m2 x 1, melphalan 60 mg/m2/d x 3 (n = 13) or thiotepa 300 mg/m2/d x 3. (n = 12), and etoposide (VP 16) 300 mg/m2/d x 3. Seventy-two hours after the last dose of VP 16, histologically tumor-free and 4-hydroperoxycyclophosphamide (4-HC; 100 mumol/L)-purged autologous bone marrow (ABMT) was infused. Acute toxicities included grade 3 to 4 oral mucositis, grade 1 to 2 diarrhea, and fevers. No patient required infusion of unpurged reserve autografts. At ABMT, 16 patients (group I) were progression-free 6.5 months to 14 months (median, 9 months) from diagnosis: seven remain progression-free 20 months to 46 months (median, 39 months) off therapy, six relapsed 4 months to 17 months post-ABMT, and three died of toxicity (candidiasis, metabolic derangement, and venoocclusive disease [VOD]). The event-free survival of group I patients is 44% at 24 months post-ABMT. Nine patients (group II) were in second remission at ABMT, including three who had relapsed after other transplant procedures: two are progression-free 24 months and 41 months off therapy, four relapsed 3 months to 12 months post-ABMT, and three died of toxicity (aspergillosis, hemorrhagic cystitis, VOD). Only one of 10 relapses involved a primary site, suggesting a beneficial effect of local radiation. In terms of survival or toxicity, an advantage for melphalan or thiotepa was not evident. Regimens such as this may prolong the survival of selected patients with poor-risk neuroblastoma, but concerns over late relapses and toxicity mandate continuing efforts to devise alternative, less risky, and more clearly beneficial approaches for definitive ablation of neuroblastoma.