International neuroblastoma staging system stage 1 neuroblastoma: a prospective study and literature review

Abstract

Purpose: To gain insight into the management of non-metastatic neuroblastoma by examining clinical and biologic features of International Neuroblastoma Staging System (INSS) stage 1 tumors.

Methods: Patients were staged by both the INSS and the Evans staging system and were evaluated for biologic prognostic factors. Patients with INSS stage 1 received no cytotoxic therapy. The literature was reviewed for clinical and biologic data about INSS stage 1.

Results: We evaluated 10 consecutive patients (median age, 17.5 months) with INSS stage 1; all remain disease-free (median follow-up duration, > 5 years). Tumors were in the abdomen (n = 6), chest (n = 3), or pelvis (n = 1). Neuroblastoma involved margins of resection in six tumors. Poor-prognostic biologic findings included tumor-cell diploidy (n = 2) and unfavorable Shimada histopathology (n = 2). Two patients were to receive chemotherapy for, respectively, a tumor deemed unresectable and a tumor classified as Evans stage III; second opinions resulted in surgical management alone in each case. Published reports confirm that some INSS stage 1 patients (1) are at risk for overtreatment, and (2) have poor-prognostic biologic findings yet do well.

Conclusion: Surgery alone suffices for INSS stage 1 neuroblastoma, even if biologic prognostic factors are unfavorable, microscopic disease remains after surgery, and tumor size is suggestive of "advanced-stage" status in other staging systems. Attempts to resect regionally confined neuroblastomas should take precedence over immediate use of cytotoxic therapy; otherwise, some patients may receive chemotherapy or radiotherapy unnecessarily.