Prognostic markers for stage 3 neuroblastoma (NB): A report from the International Neuroblastoma Risk Group (INRG) project

10009 Background: There is lack of consensus on prognostic markers other than age and tumor MYCN amplification for children with INSS stage 3 NB. Methods: The INRG database (n=8800 patients) was utilized to assess whether age, elevated ferritin (≥ 96 ng/ml), tumor histology or somatically acquired chromosomes (ch) 1p or 11q aberrations impact EFS and OS from INSS stage 3, MYCN not amplified (NA) NB. Due to the confounding of Shimada histology with age, only tumor differentiation grade and MKI were tested in multivariate models. Results: Of 1,483 patients with INSS stage 3 tumors, 1,013 had MYCN-NA tumors. Among these, 654 (64.6%) patients were age <547 days (<18 months) at diagnosis. The 5-year EFS and OS rates for patients with INSS stage 3 MYCN-NA tumors were 81%±2% and 89%±1%, respectively. Age ≥18 months at diagnosis was associated with significantly decreased EFS and OS compared to age <18 months (EFS 64%±3% vs. 90%±2% p<0.0001; OS 76%±3% vs. 95%±1%, p<0.0001). For patients <18 months of age, tumor c...