Factors Impacting Overall Survival Post‐Relapse in High‐Risk Neuroblastoma: Children's Oncology Group Outcomes From 2000 to 2019

PURPOSE: Prior studies of features impacting post-relapse survival in high-risk neuroblastoma (HRNB) evaluated patient cohorts that did not receive contemporary high-risk or relapse therapies. We describe overall survival (OS) after first progression or first relapse of HRNB in a modern cohort. METHODS: Patients with HRNB enrolled on COG ANBL00B1(NCT00904241) between 2000 and 2019, who had relapsed or progressive disease were eligible. Clinical and molecular risk factors at diagnosis, therapy era, clinical trial enrollment, and clinical features at relapse, including site of and time to relapse, were evaluated. OS post-relapse was compared between groups using log-rank tests and Cox models. RESULTS: Among 4253 eligible HRNB patients, 1616 had relapse or progression as a first event. Five-year OS post-relapse was 19.1 ± 1.1%. The risk group with the lowest post-relapse survival was observed in patients with INSS Stage 4 or 4S disease < 18 months of age at diagnosis with MYCN amplified (MYCN-A) tumors. The other significant most unfavorable factors at diagnosis included diagnosis 2000-2004, tumor MYCN-A, 1p loss of heterozygosity (LOH), and elevated LDH or ferritin. Unfavorable factors at relapse included the time to relapse < 36 months from diagnosis, and combined local and metastatic disease at relapse. Multivariable analysis indicated that those with tumors harboring 1p LOH, age ≤ 5 years at diagnosis, or earlier treatment therapy era (2000-2004) had a higher risk of post-relapse death. CONCLUSIONS: While the 5-year OS rate was low in this cohort, there are subsets of patients with relapsed HRNB who demonstrate long-term survival. TRIALS REGISTRATION: ClinicalTrials.gov identifier: NCT00904241.