Significance of MYCN Amplification in International Neuroblastoma Staging System Stage 1 and 2 Neuroblastoma: A Report From the International Neuroblastoma Risk Group Database

Purpose Treatment of patients with localized neuroblastoma with unfavorable biologic features is controversial. To evaluate the outcome of children with low-stage MYCN-amplified neuroblastoma and develop a rational treatment strategy, data from the International Neuroblastoma Risk Group (INRG) database were analyzed. Patients and Methods The database is comprised of 8,800 patients. Of these, 2,660 patients (30%) had low-stage (International Neuroblastoma Staging System stages 1 and 2) neuroblastoma, known MYCN status, and available follow-up data. Eighty-seven of these patients (3%) had MYCN amplified tumors. Results Patients with MYCN-amplified, low-stage tumors had less favorable event-free survival (EFS) and overall survival (OS) than did patients with nonamplified tumors (53% ± 8% and 72% ± 7% v 90% ± 1% and 98% ± 1%, respectively). EFS and OS were statistically significantly higher for patients whose tumors were hyperdiploid rather than diploid (EFS, 82% ± 20% v 37% ± 21%; P = .0069; OS, 94% ± 11% v ...