Impact of Initial Prognostic Factors and Intensity of Salvage Therapy on the Outcome of Progressive / Refractory High-Risk Neuroblastoma

Background: High-risk Neuroblastoma (N. B) patients have a poor outcome with 5-year survival rates of 50%. Patients with stage 4 disease or MYC-N amplification showed post-progression 5y O. S. of 7% to 8%. Other studies proved the same dismal outcome in high-risk relapsed patients. This study aimed to detect the O. S. and EFS of N. B patients post-progression. Secondary to explore, if initial prognostic factors, high-intensity salvage therapy and other treatment modalities could improve the outcome of progressive /refractory disease. Methods: Seventy patients of high-risk Neuroblastoma needed salvage therapy, either due to refractory/progressive disease or irresectability of the primary tumor. Initial prognostic factors and different treatment strategies were collected and correlated with the outcome. Results: Fifty-seven (57 /70) patients died from progressive disease with a median survival of 20.6 months with three y EFS and O. S. of 9.5% and 35.7%, respectively. Objective response (CR/VGPR/PR) post-induction, consolidation by HSCT, radiotherapy, and maintenance therapy; affected survival significantly post salvage therapy. Multivariate analysis revealed that the only independent factor that significantly affected O. S was maintenance therapy. The independent factors that affected the EFS negatively were the presence of liver metastases, poor response post-induction, and not administering radiotherapy. Conclusion: Response to induction had a significant impact on the outcome post salvage. Salvage therapy did not improve the outcome for those with inadequate induction response. Initial front-line targeted therapy like antiGD2 is needed to improve the outcome, especially for chemo-resistant ones.