Surgery as Single-Modality Treatment for Early-Stage Olfactory Neuroblastoma: An Institutional Experience, Systematic Review and Meta-analysis.

Background: For olfactory neuroblastoma (ONB), the combination of surgical tumor resection and radiation therapy (RT) has been considered the "gold standard" in treatment protocols intended to cure.

Objective: To summarize evidence on the treatment of ONB using surgery alone.

Methods: A retrospective institutional case series, a systematic review of the literature, and an individual patient data (IPD) meta-analysis on only surgically treated ONB patients.

Results: At our institution, a total of 10 patients were treated through surgery alone and remained alive and free of disease at last follow-up. The IPD meta-analysis on 128 patients revealed a disease-free survival (DFS) and overall survival (OS) of 67.7% and 75.4% at 5 years and 57.1% and 71.9% at 10 years, respectively. Univariate analysis showed that Kadish stage C/D and Hyams grading III//IV significantly affected OS (P = 0.000 and P = 0.000) and DFS (P = 0.000 and P = 0.002). For low-risk patients, the DFS was 80.6% at 5 years and 67.8% at 10 years, respectively.

Conclusions: Surgery alone is an equivalent alternative to combined treatment in carefully selected low-risk ONB patients with better outcome measures than previously reported.