The International Neuroblastoma Risk Group (INRG) Staging System: An INRG Task Force ReportPédiatrie - Publié le 05/01/2020 par Ilfad Blazevic
The International Neuroblastoma Risk Group (INRG) classification system was developed to
establish a consensus approach for pretreatment risk stratification. Because the International
Neuroblastoma Staging System (INSS) is a postsurgical staging system, a new clinical staging
system was required for the INRG pretreatment risk classification system.
To stage patients before any treatment, the INRG Task Force, consisting of neuroblastoma experts
from Australia/New Zealand, China, Europe, Japan, and North America, developed a new INRG
staging system (INRGSS) based on clinical criteria and image-defined risk factors (IDRFs). To
investigate the impact of IDRFs on outcome, survival analyses were performed on 661 European
patients with INSS stages 1, 2, or 3 disease for whom IDRFs were known.
In the INGRSS, locoregional tumors are staged L1 or L2 based on the absence or presence of one
or more of 20 IDRFs, respectively. Metastatic tumors are defined as stage M, except for stage
MS, in which metastases are confined to the skin, liver, and/or bone marrow in children younger
than 18 months of age. Within the 661-patient cohort, IDRFs were present (ie, stage L2) in 21%
of patients with stage 1, 45% of patients with stage 2, and 94% of patients with stage 3 disease.
Patients with INRGSS stage L2 disease had significantly lower 5-year event-free survival than
those with INRGSS stage L1 disease (78% 4% v 90% 3%; P .0010).
Use of the new staging (INRGSS) and risk classification (INRG) of neuroblastoma will greatly
facilitate the comparison of risk-based clinical trials conducted in different regions of the world.
Source : J Clin Oncol 27:298-303