Analysis of DNA ploidy and proliferative activity in relation to histology and N-myc amplification in neuroblastoma.
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.
Cohn
S L
SL
Department of Pediatrics, Northwestern University, Chicago, Illinois.
Rademaker
A W
AW
Salwen
H R
HR
Franklin
W A
WA
Gonzales-Crussi
F
F
Rosen
S T
ST
Bauer
K D
KD
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
D004247:DNA