THE PEDIATRIC-ONCOLOGY-GROUP EXPERIENCE WITH THE INTERNATIONAL STAGING SYSTEM CRITERIA FOR NEUROBLASTOMA

Purpose: An international consensus on the criteria for surgicopathologic staging (INSS) of patients with neuroblastoma has been published, but has not been validated. A retrospective study was conducted to assess if the INSS definitions identified prognostic subsets of patients with neuroblastoma. Patients and Methods: The initial operative and pathology reports were reviewed from 675 patients on Pediatric Oncology Group (FOG) #8104, a stage- and age-related treatment study that used the FOG surgicopathologic staging system. Results: Of 596 eligible cases, there was concordance between the FOG and INSS stages for the 193 patients with localized, resected disease (FOG stage A), the 202 with distant metastases, the 51 with FOG stage Ds (IVs) tumors, and 40 of the cases with grossly unresected, localized tumor without lymph node involvement (FOG stage B). Of the remaining 19 patients with FOG stage B tumors, five were INSS stage 2B and 14 INSS stage 3. All of the 91 cases with nonadherent, regional lymph node metastases (FOG stage C) conformed to the definitions for INSS stage 2B (n = 42) or 3 (9 = 49). In infants, there was no difference in event-free survival (EFS) among INSS stages 2A, 2B, or 3. In contrast, older children with INSS stage 3 disease had inferior EFS compared with INSS stage 2A or 2B tumors. Conclusion: We conclude the following: (1) the INSS identifies distinct patient subsets, particularly in children; (2) infants remain a favorable group, regardless of INSS/FOG stage; and (3) the INSS deserves further prospective study especially in the light of recent biologic prognostic variables.