Treatment Outcomes of Olfactory Neuroblastoma: A Multicenter Study by the Korean Sinonasal Tumor and Skull Base Surgery Study Group

Objectives. Due to the rarity of olfactory neuroblastoma (ONB), there is ongoing debate about optimal treatment strategies, especially for early-stage or locally advanced cases. Therefore, our study aimed to explore experiences from multiple centers to identify factors that influence the oncological outcomes of ONB. Methods. We retrospectively analyzed 195 ONB patients treated at nine tertiary hospitals in South Korea between December 1992 and December 2019. Kaplan-Meier survival analysis was used to evaluate oncological outcomes, and a Cox proportional hazards regression model was employed to analyze prognostic factors for survival outcomes. Furthermore, we conducted 1:1 nearest-neighbor matching to investigate differences in clinical outcomes according to the use of neoadjuvant chemotherapy. Results. In our cohort, the 5-year overall survival (OS) rate was 78.6%, and the 5-year disease-free survival (DFS) rate was 62.4%. The Cox proportional hazards model revealed that the modified Kadish (mKadish) stage and Dulguerov T status were significantly associated with DFS, while the mKadish stage and Hyams grade were identified as prognostic factors for OS. The subgroup analyses indicated a trend toward improved 5-year DFS with dural resection in mKadish A and B cases, even though the result was statistically insignificant. Induction chemotherapy did not provide a survival benefit in this study after matching for the mKadish stage and nodal status. Conclusion. Clinical staging and pathologic grading are important prognostic factors in ONB. Dural resection in mKadish A and B did not show a significant survival benefit. Similarly, induction chemotherapy also did not show a survival benefit, even after stage matching.