Prognostic Utility of Hyams Histological Grading and Kadish-Morita Staging Systems for Esthesioneuroblastoma Outcomes

Background Esthesioneuroblastoma (ENB) is derived from the specialized olfactory neuroepithelium. Hyams grading and Kadish staging have been used to prognosticate and to guide treatment decisions. In this study, we sought to validate the prognostic utility of these systems in a large ENB cohort. Methods We retrospectively analyzed the records of patients with ENB who had been evaluated and treated at our institution. The association of grade and stage with prognostic outcome was assessed; the Kaplan-Meier estimator was used to generate 5-year OS and DFS curves. Results Out of 124 cases we identified, 121 were assessed for grading and 109 for staging. Review of the tissue samples revealed that 62% of tumors were low grade (I/II) and 21% were high grade (III/IV); 17% of tumors were metastasis. The OS rate was 75% at 5 years. The DFS was 60% at 5 years. The OS was significantly worse for metastatic ENB (low-grade ENB vs metastatic ENB, p = 0.01598); the DFS was significantly worse for high grade versus low grade ENB. Of the 109 cases that had been staged, 16% were stage A, 33% stage B, 43% stage C, and 8% stage D. In the A, B, and C groups, there were no significant differences between recurrence, distant metastasis, or 5-year survival rates. Statistical significance was neither reached with T, N, M and overall staging system. Age cutoff of 65 years reliably predicted OS. Conclusions High grade of ENB was significantly associated with poor outcome, while advanced stage was not associated with poor outcome in this large cohort. Grading should certainly be considered in prognostication and treatment decisions for ENB.