Efficacy of Post-induction Therapy for High-risk Neuroblastoma Patients with End-induction Residual Disease

Background: High-risk neuroblastoma patients with end-induction residual disease commonly receive post-induction therapy in an effort to increase survival by improving the response before autologous stem cell transplantation (ASCT). The authors conducted a multicenter, retrospective study to investigate the efficacy of this approach.

Methods: Patients diagnosed between 2008 and 2018 without progressive disease with a partial response or worse at end-induction were stratified according to the post-induction treatment: 1) no additional therapy before ASCT (cohort 1), 2) post-induction "bridge" therapy before ASCT (cohort 2), and 3) post-induction therapy without ASCT (cohort 3). χ tests were used to compare patient characteristics. Three-year event-free survival (EFS) and overall survival (OS) were estimated by the Kaplan-Meier method and survival curves were compared by log-rank test.

Results: The study cohort consisted of 201 patients: cohort 1 (n = 123), cohort 2 (n = 51), and cohort 3 (n = 27). Although the end-induction response was better for cohort 1 than cohorts 2 and 3, the outcomes for cohorts 1 and 2 were not significantly different (P = .77 for EFS and P = .85 for OS). Inferior outcomes were observed for cohort 3 (P < .001 for EFS and P = .06 for OS). Among patients with end-induction stable metastatic disease, 3-year EFS was significantly improved for cohort 2 versus cohort 1 (P = .04). Cohort 3 patients with a complete response at metastatic sites after post-induction therapy had significantly better 3-year EFS than those with residual metastatic disease (P = .01).

Conclusions: Prospective studies to confirm the benefits of bridge treatment and the prognostic significance of metastatic response observed in this study are warranted.