TREATMENT OF POOR-RISK NEUROBLASTOMA PATIENTS WITH HIGH-DOSE CHEMOTHERAPY AND AUTOLOGOUS PERIPHERAL STEM-CELL RESCUE

A single institutional pilot study was conducted in which 12 poor-risk neuroblastoma (NB) patients were uniformly treated with multi-agent i nduction chemotherapy followed by myeloablative consolidation chemothe rapy and unpurged peripheral blood stem cell (PBSC) rescue. In additio n to using standard criteria for evaluating response to induction chem otherapy, tumor cell contamination of the peripheral blood and/or bone marrow was analyzed in seven patients by immunocytology using a panel of five anti-NB monoclonal antibodies. Seven patients had morphologic evidence of bone marrow disease at the time of diagnosis, and two add itional patients had tumor cells detected in bone marrow samples by im munocytology prior to the second cycle of chemotherapy. After three cy cles of chemotherapy, two of the 12 patients continued to have evidenc e of bone marrow disease. Samples from 29 PBSC harvests collected from nine patients were also analyzed for the presence of contaminating tu mor cells by immunocytology. In each case, the stem cells were found t o be free of tumor. Eleven of the 12 patients underwent myeloablative therapy and PBSC rescue; five patients remain alive without disease pr ogression, 28+ to 53+ months from diagnosis, and six patients have dev eloped recurrent disease. We conclude that PBSCs can be successfully h arvested from children with NB, and used for hematopoietic reconstitut ion following myeloablative chemotherapy. However, more effective ther apy for poor-risk NB patients is still urgently needed.