Patterns of failures after surgical resection in olfactory neuroblastoma.

Abstract

Patterns of failure in patients with olfactory neuroblastoma (ONB) according to two surgical approaches, craniofacial resection (CFR) and endoscopic surgery (ENDO), have yet to be analyzed. We retrospectively reviewed 28 patients with surgically treated ONB between January 1995 and October 2017. Fourteen (50.0%) patients underwent CFR (9 CFR alone, 5 ENDO-assisted CFR) and 14 (50.0%) underwent ENDO. Nineteen (67.9%) patients underwent post-operative radiotherapy (RT). At a median follow-up of 53.8months (range 10.4-195.3), the 5-year progression-free survival (PFS) and 10-year overall survival were 37.3% and 57.5%, respectively. Patients with adjuvant RT had a 5-year PFS of 46.7%, whereas those treated with surgery alone had a 5-year PFS of 19.4% (p = 0.01). Locoregional failure (LRF) occurred in ten patients (median 59.6months after initial diagnosis; range 12.7-59.7). Neck node metastasis occurred in 25.0% (7 of 28). Five patients with ENDO showed LRF and underwent proper subsequent treatments with either surgery or adjuvant RT. Approximately 35.7% patients (five patients) in the CFR group experienced distant metastasis in the intracranial dura region (median 116.4months after initial diagnosis; range 2.6-142.4). Three of four patients who developed LRF after CFR developed dura-based metastasis. Both dura-based and neck node metastasis in the delayed phase were distinct patterns of failure in ONB. Patterns of recurrence differed based on surgical approach; dura-based metastases were common after CFR. LRF was the distinct failure pattern in ENDO, but could be successfully salvaged. Treatment outcome was improved considerably with RT following surgical resection.