# Nationwide analysis of olfactory neuroblastoma in Japan: evolving treatment approaches and prognostic outcomes

## TL;DR

This study analyzed olfactory neuroblastoma cases in Japan, finding increased use of endoscopic surgery and better survival in younger and female patients.

## Contribution

The study provides nationwide insights into treatment trends and survival outcomes for olfactory neuroblastoma in Japan.

## Key findings

- Endoscopic surgery became more common compared to open skull base surgery.
- Younger patients and females had better overall survival.
- Postoperative radiotherapy improved recurrence-free survival but not overall survival.

## Abstract

Olfactory neuroblastoma (ONB) is a rare malignant tumor of the nasal cavity and paranasal sinuses. In this study, we aimed to analyze ONB cases registered in the nationwide Head and Neck Cancer Registry of Japan.

Among 90 885 head and neck cancer registrations (2011–19), we identified 346 patients with ONB. We summarized demographics, tumor-node-metastasis (TNM) classification, and treatment modalities (surgery, radiotherapy, chemotherapy) and compared patterns between an early (2011–15) and a late (2016–19) period. Survival was analyzed in 95 patients with standardized 5-year outcomes available.

T4 lesions were frequent, and 234 patients (67.6%) received surgery-based treatment, typically combined with postoperative radiotherapy. Over time, endoscopic approaches increased markedly and became predominant over open skull base surgery. Among the 95 patients with evaluable follow-up, the 5-year overall survival (OS) and 5-year recurrence-free survival (RFS) were 85.1% and 62.7%, respectively. Patients <60 years old and female patients exhibited better OS compared to younger patients and males. Postoperative radiotherapy was associated with improved RFS but not OS. Chemotherapy was used more often with open skull base surgery than with other surgical approaches.

Endoscopic surgery for ONB rose substantially, while younger age and female sex were associated with better OS, and postoperative radiotherapy was correlated with improved RFS.

Analyzed nationwide data on olfactory neuroblastoma in Japan, highlighting increased endoscopic surgery, survival differences by age and sex, and improved recurrence-free survival with postoperative radiotherapy.