MYCN oncogene amplification in neuroblastoma is associated with worse prognosis, except in stage 4s: the Italian experience with 295 children.

ABSTRACT

PURPOSE: To evaluate the prognostic role of MYCN oncogene amplification in children with neuroblastoma. PATIENTS AND METHODS: Of 694 children (age, 0 to 15 years) with previously untreated neuroblastoma, 295 (42%) were evaluated at diagnosis for MYCN gene amplification. RESULTS: Clinical characteristics and survival results of 295 patients studied and 399 not studied for MYCN were comparable. In 48 of 295 patients studied for MYCN (16%), the gene was amplified (> or = three gene copies). Amplification was more frequent in children older than 1 year, with abdominal tumor (18% v 7%), advanced disease, normal vanillylmandelic (VMA) urinary excretion, and high lactate dehydrogenase (LDH), ferritin, and neuron-specific enolase (NSE) serum levels. In patients studied for MYCN, the 5-year overall survival (OS) rate was higher for children aged less than 1 year (90% v 44%), with extraabdominal tumor, stage 1 or 2 versus 3 versus 4, and normal NSE, LDH, and ferritin serum levels. Patients with amplified MYCN had a worse OS (odds ratio [OR], 3.38; confidence interval [CI], 2.22 to 5.16). This association held after adjustment for other characteristics. The impact of MYCN amplification was greater in patients with favorable characteristics, in particular age (OR, 10.28 for infants; 2.08 for older children) and stage (OR, 35.3 for stage 1 to 2; 8.41 for stage 3; 1.76 for stage 4). However, of 29 children with stage 4s, all three with amplified MYCN survive. In a multivariate analysis, the prognostic role of MYCN amplification, age, and stage was confirmed, but the size of the effect of MYCN was dependent on age and stage. CONCLUSION: MYCN amplification is associated with a worse prognosis in children with neuroblastoma at all ages and stages except 4s. This association is most pronounced in children with otherwise favorable prognostic indicators, and in these children should be considered as an indication for more intensive intervention.