PROGNOSTIC-SIGNIFICANCE OF MYCN ONCOGENE EXPRESSION IN CHILDHOOD NEUROBLASTOMA

Purpose: To assess the significance of MYCN gene expression as a progn ostic factor in patients with neuroblastoma of various ages, and to de termine whether it can predict for outcome independently of MYCN gene amplification. Patients and Methods: The level of MYCN gene expression in 60 specimens of primary untreated neuroblastoma was determined by reverse-transcriptase polymerase chain reaction (RT-PCR) analysis, Res ults: High levels of MYCN gene expression were associated with advance d tumor stage (P =.0005), with the presence of MYCN gene amplification (P <.000l), but not with older age at diagnosis. Among patients who l acked MYCN gene amplification, the levels of MYCN gene expression were significantly greater in the tumors of infants compared with those of older children (P <.0005), High MYCN expression was strongly associat ed with reduced survival and event-free survival in the overall study population (P <.005), and also in the subset of patients aged older th an 1 year at diagnosis (P <.001), In contrast, MYCN expression did not appear to be predictive of outcome in infants. After adjustment for t he effect of MYCN amplification, high levels of MYCN expression retain ed significant prognostic value for poor survival (relative hazards, 3 0.3; P =.003) in children aged older than 12 months at diagnosis, Conc lusion: High MYCN gene expression is strongly predictive of poor outco me in older children with neuroblastoma, but not in infants. The findi ngs help explain the controversy in the literature about the prognosti c value of MYCN gene expression a nd high light the different biology of neuroblastoma that presents in infants and older children. (C) 1998 by American Society of Clinical Oncology.