Different karyotypic patterns in early and advanced stage neuroblastomas.

Of 23 untreated and 7 treated (relapsed) neuroblastomas, 14 (11 untreated, 3 treated) had modal chromosome numbers in the diploid (45 to 51), 9 (8 untreated, 1 treated) in the triploid (60 to 77), and 6 (3 untreated, 3 treated) in the hypotetraploid (81 to 88) range, and one (untreated) had hypertetraploidy (100). The near-or-pseudodiploid and hypotetraploid tumors were characterized by numerous structural abnormalities, most frequently of 1p, and frequent presence of double minutes or homogeneously staining regions. The near-triploid tumors were characterized by three almost complete haploid sets of chromosomes, and few structural abnormalities. N-myc amplification was found in five of the near-or-pseudodiploid or hypotetraploid tumors but in none of the near-triploid tumors. Most near-triploid tumors were found in infants at stage I or II, and the near-or-pseudodiploid or hypotetraploid tumors in children at stage II or IV mostly 1 year old or older. Among the untreated patients, all 8 with a near-triploid tumor were alive with no evidence of the disease, and the 11 with a near-or-pseudodiploid tumor had a median survival of only 376 days (P less than 0.05), 7 of the 11 being dead. Thus, the near-triploid patients had well recognized favorable prognostic factors and an excellent prognosis, and the near-or-pseudodiploid patients had unfavorable prognostic factors and a dismal prognosis. The hypotetraploid tumors seemed to have karyotypic and clinical features in common with the near-or-pseudodiploid tumors. We presume that the near-triploid tumors and the near-or-pseudodiploid or hypotepraploid tumors may constitute distinctly different subcategories within neuroblastomas.