title: Analysis of DNA ploidy and proliferative activity in relation to histology and N-myc amplification in neuroblastoma.
abstract: Diploid DNA content, advanced stage, unfavorable histology, and N-myc amplification are all associated with aggressive disease and poor prognosis in childhood neuroblastoma. DNA diploidy is associated with advanced stage and unfavorable histology, but the relationships among ploidy, N-myc amplification, and proliferative activity are not known. To determine if DNA diploidy is associated with N-myc amplification, we studied 29 neuroblastomas with flow cytometric analysis and Southern blot analysis. Clinical and histologic features were also evaluated. Sixty percent of the N-myc-amplified tumors were diploid, compared to 26% of the neuroblastomas, which lacked N-myc amplification (P = 0.11). In our analysis of proliferative activity and N-myc amplification, a higher mean percentage of cells in S phase was seen in the N-myc-amplified tumors (13.4%) than in the unamplified tumors (10%), but again the result was not statistically significant (P = 0.14). Significant associations were seen between unfavorable histology and DNA diploidy (P = 0.05), and between unfavorable histology and high proliferative activity (P = 0.007). Our data suggest that biologic factors other than N-myc amplification play a role in determining the aggressiveness of at least some diploid neuroblastomas.
authors.affiliation: Department of Pediatrics, Northwestern University, Chicago, Illinois.
authors.forename: S L
authors.initials: SL
authors.lastname: Cohn
authors.forename: A W
authors.initials: AW
authors.lastname: Rademaker
authors.forename: H R
authors.initials: HR
authors.lastname: Salwen
authors.forename: W A
authors.initials: WA
authors.lastname: Franklin
authors.forename: F
authors.initials: F
authors.lastname: Gonzales-Crussi
authors.forename: S T
authors.initials: ST
authors.lastname: Rosen
authors.forename: K D
authors.initials: KD
authors.lastname: Bauer
mesh_terms: D015139:Blotting, Southern; D002675:Child, Preschool; D004247:DNA / Q000235:genetics*; D005434:Flow Cytometry; D005784:Gene Amplification; D006801:Humans; D007223:Infant; D007399:Interphase; D009447:Neuroblastoma / Q000235:genetics* / Q000473:pathology; D009857:Oncogenes; D011003:Ploidies
chemical_list: D004247:DNA