Chemotherapy in Esthesioneuroblastoma/Olfactory Neuroblastoma: An Analysis of the Surveillance Epidemiology and End Results (SEER) 1973-2015 Database

Objective:Chemotherapy has been proposed as an adjunct to primary local therapy in esthesioneuroblastoma (ENB)/olfactory neuroblastoma (ON), but its role has not been precisely defined. Here, we evaluated its role in ENB treatment.Materials and Methods:The Surveillance Epidemiology and End Results (SEER) database was queried for ENB/ON (International Classification of Diseases-3 9522). Cases met criteria for inclusion if they were unique, had a primary location in the nasal cavity, and had adequate information for Kadish staging derivation. Univariable and multivariable Cox analyses assessed chemotherapy treatment effect on disease-specific survival (DSS) and overall survival (OS). Multiple imputation addressed missing data. A P<0.05 was designated for statistical significance.Results:In adjusted multivariable analyses, chemotherapy treatment was associated with inferior DSS (hazard ratio [HR], 1.74; 95% confidence interval [CI], 1.21-2.51; P=0.003) and OS (HR, 1.71; 95% CI, 1.26-2.32; P=0.001). Among the subset with local or regional disease treated with surgery and/or radiation therapy, chemotherapy remained associated with inferior outcomes DSS (HR, 2.78; 95% CI, 1.63-4.74; P<0.001) and OS (HR, 2.18; 95% CI, 1.45-3.27; P<0.001). Chemotherapy treatment misclassification did not explain these findings.Conclusions:This analysis does not support chemotherapy to improve either DSS or OS in primary ENB/ON treatment, after controlling for known ENB prognostic factors available from SEER. Other prognostic and treatment selection factors could exist which were not controlled in these analyses. Chemotherapy could beneficially affect outcomes other than DSS or OS. Although the concerns have been expressed regarding chemotherapy treatment misclassification in SEER, their analyses did not identify such misclassification as an explanation for our findings.