Time to Esthesioneuroblastoma Recurrence: A Meta-Analysis

Objective: Esthesioneuroblastoma (ENB) is a rare sinonasal malignancy believed to arise from the olfactory epithelium. As noted in the literature, initial local tumor recurrence or metastasis can occur many years after primary treatment, necessitating long-term follow-up. However, there is no consensus regarding frequency of surveillance after initial treatment. The purpose of this study is to identify the average time to recurrence to better define optimal follow-up in ENB patients.

Methods: A search of the MEDLINE database for English-language publications containing the keywords “esthesioneuroblastoma” or “olfactory neuroblastoma” from January 1990 to September 2012 was performed. Case series with a minimum of four patients and presenting sufficient recurrence and follow-up data were included for analysis. A weighted average of the time to recurrence for the overall cohort was performed. Studies providing sufficient individual follow-up data were compiled separately, and Kaplan-Meier survival curves were calculated for overall and recurrence-free survival. Statistical analysis was performed using the SAS 9.3 software package (Cary, NC).

Results: A total of 637 patients from 38 studies were identified with an overall recurrence rate of 42.8%. The weighted time to recurrence was 36.3 months at all sites and 35.2 months locally.

There were sufficient data for 277 patients to undergo Kaplan-Meier survival analysis. Overall and recurrence-free survival at 5 years was 71.1% and 51.4%, respectively. Mean time to local, regional, and distant recurrence was 39.8, 33.1, and 16.9 months, respectively.

Conclusion: Based on the data in the literature, most ENB recurrences will occur 5 years or sooner following initial therapy. Further study is required to identify predictors of late recurrence or metastasis.