MORPHOLOGIC AND MOLECULAR CYTOGENETICS IN NEUROBLASTOMA

Background. Some genetic alterations have been shown to have prognostic implication for patients with neuroblastoma: MYCN oncogene amplification, deletion of the short arm of chromosome 1 and di- or tetraploidy. The goal of this study was to analyze these factors in children with neuroblastoma. Methods. Twenty neuroblastoma samples were analyzed with morphologic cytogenetics, and each of them was compared with MYCN amplification status by Southern blot and fluorescent in situ hybridization (FISH) with a genomic probe. Results. A complete karyotype was obtained for 14 children. A diploid or tetraploid mode and a 1p deletion were found in most children with advanced stages, MYCN amplification status was totally concordant with both methods in all patients, even in a case with low level amplification. A wide intercellular variation in the amplification level in each MYCN amplified sample was shown. Conclusion. The use of FISH to assess MYCN amplification rapidly in neuroblastoma is recommended. This method could be very useful in future therapeutic protocols in which treatment is based on MYCN status (and especially for infants and children with localized tumor).