Revisions of the international criteria for neuroblastoma diagnosis, staging, and response to treatment.

PURPOSE AND METHODS: Based on preliminary experience, there was a need for modifications and clarifications in the International Neuroblastoma Staging System (INSS) and International Neuroblastoma Response Criteria (INRC). In 1988, a proposal was made to establish an internationally accepted staging system for neuroblastoma, as well as consistent criteria for confirming the diagnosis and determining response to therapy (Brodeur GM, et al: J Clin Oncol 6:1874-1881, 1988). A meeting was held to review experience with the INSS and INRC and to revise or clarify the language and intent of the originally proposed criteria. Substantial changes included a redefinition of the midline, restrictions on age and bone marrow involvement for stage 4S, and the recommendation that meta-iodobenzylguanidine (MIBG) scanning be implemented for evaluating the extent of disease. Other modifications and clarifications of the INSS and INRC are presented. In addition, the criteria for the diagnosis of neuroblastoma were modified. Finally, proposals were made for the development of risk groups that incorporate both clinical and biologic features in the prediction of prognosis. The biologic features that were deemed important to evaluate prospectively included serum ferritin, neuron-specific enolase (NSE), and lactic dehydrogenase (LDH); tumor histology; tumor-cell DNA content; assessment of N-myc copy number; assessment of 1p deletion by cytogenetic or molecular methods; and TRK-A expression. RESULTS AND CONCLUSION: Modifications of the INSS and INRC made at this conference are presented. In addition, proposals are made for future modifications in these criteria and for the development of International Neuroblastoma Risk Groups.