Abstract 4192: Increasing incidence of EBV-related nasopharyngeal carcinoma in the United States

Abstract

Abstract Purpose: Incidence of nasopharyngeal carcinoma (NPC) is highly geographically variable and historically rare in the US. While etiological factors differ by histological subtype, Epstein-Barr virus (EBV) is generally accepted as the primary risk factor for non-keratinizing NPC. In light of the changing epidemiology of HPV-associated oropharyngeal cancer, it is important to evaluate temporal incidence of NPC in the US. Methods: Incidence and survival data from 1973-2015 were obtained from the Surveillance, Epidemiology and End Results (SEER) Program. Stratified analyses were conducted to assess temporal trends in NPC by histological subtype, sex and race. The data were analyzed using SAS 9.4 and Joinpoint Regression Software to determine age-adjusted incidence rates, trends in annual percent change (APC) as well as calculate 5-year relative survival estimates and Kaplan-Meier curves. Results: Although overall NPC incidence is decreasing in the US, the non-keratinizing differentiated subtype appears to be starkly increasing with an APC of approximately 4% among white males (95%CI: 2.5, 5.2), white females (95%CI: 1.9, 6.2), and black males (95%CI: 2.0, 5.7), 2.7% among black females (95%CI: 0.8, 4.6) and 1.8% among women of other race (95%CI: 0.4, 3.3). When compared to other histological subtypes, patients with keratinizing squamous cell carcinoma had the worst survival (log rank p<0.001). Additional survival disparities were noted, with black males having consistently poorer survival across all histological subtypes, and those individuals in the “other” race category, particularly females, experiencing the highest 5-year relative survival estimates. Conclusions: Although NPC remains relatively rare in the overall US population, there is evidence to suggest that the EBV-related differentiated subtype is increasing across all genders and races. Citation Format: Ilona Argirion, Katie R. Zarins, Julie J. Ruterbusch, Patravoot Vatanasapt, Hutcha Sriplung, Erlene K. Seymour, Laura S. Rozek. Increasing incidence of EBV-related nasopharyngeal carcinoma in the United States [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 4192.