[The prognostic effect of amplification of the MYCN oncogene in neuroblastoma. The preliminary results of the Italian Cooperative Group for Neuroblastoma (GCINB)].

Of 567 children with neuroblastoma diagnosed between November 1984 and May 1993 in 21 Italian institutions, 235 (41%) have been evaluated for MYCN oncogene amplification. The amplification (3 or more copies of the gene) was found in 39 patients (17%) and was more frequent in patients aged more than one year, abdominal primary site of the tumor, advanced stages, normal urinary excretion of vanillylmandelic acid (VMA), and high level of LDH, NSE and ferritin. The five-year survival of the 235 patients (62%) was significantly better in patients with normal copy number of MYCN (69% versus 29%). By correlating genomic amplification with clinical and biochemical characteristics, MYCN amplification was found associated with a worse prognosis even when patients were subdivided for age (under and above one year), disease extension (localized operable, localized but inoperable, and disseminated) with exception for Stage IV-S, VMA and homovanillic acid excretion, serum levels of NSE and ferritin, but not of LDH. These data confirm the unfavourable prognostic meaning of MYCN amplification, but are unable to define if it represents a new independent variable.