Similar chromosomal patterns and lack of N-myc gene amplification in localized and IV-S stage neuroblastomas in infants.

Chromosome analysis was performed on 33 neuroblastomas in infants. Near triploid chromosome abnormalities (range, 60 to 77) were found in 29 patients with localized and IV-S stage neuroblastoma, and hyperdiploidy (range, 50 to 56) in 3 patients with localized neuroblastoma. No marker chromosome 1, homogeneously staining region (HSR), or double minutes (DMS) was observed in these patients, all of which have been previously reported in advanced neuroblastomas. N-myc gene amplification was not detected in any of these patients. All the patients were completely free of disease 4-45 months after diagnosis. Only one patient with stage IV neuroblastoma had a marker chromosome 1 (mode 46) and N-myc gene amplification and relapsed. Five patients with IV-S neuroblastoma lacking N-myc gene amplification had near triploid chromosomal abnormalities similar to those seen in localized neuroblastoma in infants. We consider that, cytogenetically, localized and IV-S neuroblastoma may be within the same disease category and different from advanced neuroblastoma.