Abstract 5047: Change in age of diagnosis of oropharyngeal cancer in the United States, 1975-2015

Introduction: Human papillomavirus (HPV) is the most common etiology of oropharyngeal squamous cell carcinoma (OPSCC), causing 70-90% of cases, and has continued to increase in incidence. While HPV-associated OPSCC has been associated with younger age at diagnosis compared to other head and neck cancers, research studies suggest that age of diagnosis might have increased in the last decade. There is currently no long-term, population-based estimate of age of diagnosis of oropharyngeal cancer, or differences in age of diagnosis based on race and gender. This study aimed to describe the change if any in the age of diagnosis of OPSCC in the last four decades. Methods: The mean age at diagnosis of OPSCC patients from the Surveillance, Epidemiology, and End Results (SEER) 9 database diagnosed from 1975-2015 was computed for each year (n = 30,320). An independent samples t-test compared mean age at diagnosis by sex (female, male), and analysis of variance compared mean age at diagnosis by race/ethnicity (Hispanic, non-Hispanic (NH) white, NH black, NH other). Joinpoint regression estimated yearly increases/decreases in mean age of diagnosis by sex and race/ethnicity through annual percent changes (APC), which were summarized with average annual percent changes (AAPC). Results: OPSCC patients were predominantly NH white (80.0%) and male (76.8%) with a mean age at diagnosis of 60.3 years (standard deviation = 10.9 years). Females had a significantly higher mean age at diagnosis than males (62.4 versus 59.7, p 0.05), significantly decreased from 1996-2002 (APC=-0.86, p 0.05). The AAPCs in age of diagnosis for gender (males and females) and race/ethnicity also both remained stable from 1975-2015 (p > 0.05), except for NH blacks, with an estimated 0.13% yearly increase in age of diagnosis from 1975-2015 (AAPC = 0.13, p Conclusions: The overall age at diagnosis for OPSCC has remained stable in the United States between 1975 and 2015. The younger age at diagnosis among NH blacks and Hispanics is important in prevention, early detection, and surveillance of OPSCC in the United States Citation Format: Brittany J. Cline, Matthew C. Simpson, Aleksandr R. Bukatko, Eric Adjei Boakye, Kahee A. Mohammed, Nosayaba Osazuwa-Peters. Change in age of diagnosis of oropharyngeal cancer in the United States, 1975-2015 [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 5047.