[Maturation therapy for advanced neuroblastoma-therapeutic effects and problems]

Seven children with advanced neuroblastoma were treated with maturation therapy. This therapy consisted of 12 hours drip infusion of papaverine (40-45 mg/kg/day) for 2 days with or without high dose cyclophosphamide (2,000-3,600 mg/m2). During maturation therapy all patients received intravenous hyperalimentation. One patient who had received papaverine alone did not respond to the therapy. Among 6 patients treated with papaverine and high dose cyclophosphamide, 3 responded to the therapy, 2 did not and one died soon after the therapy. However, similar responses were obtained in 2 of 3 responders with high dose cyclophosphamide alone. After all, papaverine infusion was evaluated to be effective only in one patient. The clinically severe complications of papaverine infusion were somnolence in all patients and extrapyramidal symptoms in 6 patients. Because of these extremely high toxicity rates with little evidence of therapeutic effect, selection for this therapy should be carefully done and the treatment plan should be reconsidered.