Treatment modalities and outcomes of olfactory neuroblastoma.

OBJECTIVES/HYPOTHESIS: To analyze the clinical features of olfactory neuroblastoma (ONB) and compare the treatment results according to various treatment modalities, and to validate various staging systems.

STUDY DESIGN: Retrospective analysis.

METHODS: This study included 35 patients with ONB. Treatment consisted of neoadjuvant chemotherapy and radiation therapy (seven patients), traditional craniofacial resection (TCFR, 12 patients), endoscopic craniofacial resection with craniotomy (ECFR, 11 patients), and transnasal endoscopic resection without craniotomy (five patients). The overall mean follow-up period was 64.9 months and mean disease-free survival (DFS) was 50.2 months.

RESULTS: Five-year overall survival and 5-year DFS rates were 76.0% and 61.8%, respectively. Five-year DFS rates for nonsurgical treatment, TCFR, ECFR, and transnasal endoscopic resection without craniotomy group were 35.7%, 41.7%, 80.8%, and 100%, respectively (P = .01). Neck metastasis negatively affected survival (P = .03). DFS rate of patients in the endoscopic surgery group was higher than the nonendoscopic surgery group on Cox multivariate regression analysis (P = .02). The modified Kadish classification system predicted DFS more accurately than the Biller and Dulguerov classification system (P = .04). Locoregional recurrence occurred in 23% (period of recurrence after treatment, mean 49 months; range, 3-143) of patients with ONB, and distant metastasis in 26%. ECRF group showed lesser perioperative bleeding amount and shorter operation time compared with TCFR. However, the admission period was not statistically different.

CONCLUSIONS: Endoscopic surgery for advanced ONB showed successful survival results compared with nonendoscopic surgery on multivariate analysis, and limited morbidities. Modified Kadish classification best predicted DFS for ONB. Long-term follow-up is necessary due to its late recurrence.