Transplantation for ultra high-risk neuroblastoma patients: effect of tandem autologous stem cell transplantation

Abstract

Aim: Neuroblastoma is a tumor with a high mortality rate originating from primitive sympathetic ganglion cells. In recent years, the definition of "ultra high-risk" has been used, in which the response to treatment is added in addition to the disease characteristics. In this study, the results of tandem high-dose Iodine 131 (131I) metaiodobenzylguanidine (MIBG) and tandem autologous hematopoietic stem cell transplantation (HSCT) in patients who were diagnosed as refractory after first-line treatments and considered with ultra-high risk nöroblastom (NBL) in Erciyes University Medical Faculty Pediatric Bone Marrow Transplant Center were shared.
 Material and Method: Eleven patients who underwent tandem MIBG and autologous HSCT with the diagnosis of refractory/ultra high-risk NBL between 2011 and 2021 were included in the study. Patient's data were obtained retrospectively using an electronic or manuscript medical record.
 Results: Tandem autologous HSCT and MIBG treatment were applied to 11 patients with a median age of 40.5 months who were diagnosed with refractory/ultra high-risk neuroblastoma. In our study, the overall survival rate was 54.5% and event-free survival (EFS) was 39% at a median follow-up of 20.7 (7.8-105.6) months. Of the 6 surviving patients, 4 are followed in complete remission and 2 in partial remission.
 Conclusion: Our study is the only study that includes a group of patients who received tandem high-dose MIBG and tandem autologous HSCT transplantation in refractory NBL patients without cytokine and immunotherapy. Tandem transplantation and MIBG therapy in ultra-high-risk NBL cases remain promising with acceptable toxicity. Adding immunotherapy to this treatment protocol and combining it with new treatment modalities such as anaplastic lymphoma kinase (ALK), which also takes into account genetic characteristics, may increase survival and event-free survival rates.