Clinical, Biologic, And Outcome Differences According To Mibg Avidity In Children With Neuroblastoma: A Report From The Children'S Oncology Group (Cog).

10526Background: Prior investigations suggest that neuroblastomas (NBL) that do not accumulate MIBG (MIBG non-avid) may have more favorable features compared to MIBG avid tumors. We compared clinical/biologic features and clinical outcomes between patients with MIBG non-avid vs. avid NBL. Methods: A retrospective analysis was performed of patients with metastatic high- or intermediate-risk NBL treated on COG protocols A3973 or A3961, respectively. A3973 patients had baseline MIBG scans centrally reviewed (n = 306). A3961 patients with bone metastasis at baseline were included (n = 37). Comparisons of clinical/biological features according to MIBG avidity were made with chi-squared or Fisher exact tests. Event-free survival (EFS) was compared using log-rank tests and modeled using Cox models. Results: Thirty of 343 patients (8.7%) in the analytic cohort had MIBG non-avid NBL (n = 1 from A3961 and n = 29 from A3973). Non-avid tumors were less likely to be adrenal primary tumors (34.5% vs. 57.2%; p = 0.02) o...