Abstract D128: Oropharyngeal cancer incidence-based mortality trends in the United States, 1985-2016

Objective: The last three decades in the United States have seen oropharyngeal cancer emerge as an important human papillomavirus (HPV)-associated cancer, with about three-quarters of cases thought to be positive for HPV. It has dramatically increased in incidence and recently surpassed cervical cancer as the leading HPV-associated cancer. While positive HPV tumor status generally portends better survival probability compared with non-HPV related head and neck cancer, there is a paucity of data describing mortality trends. This study aimed to describe trends in oropharyngeal cancer incidence-based mortality in the United States in the last three decades. Methods: We estimated age-adjusted incidence-based mortality rates (AAMR) from first primary oropharyngeal squamous cell carcinoma (OPSCC), using the Surveillance, Epidemiology, and End Results (SEER) 9 database from 1985-2016. To prevent later years from having a cumulatively larger set of patients diagnosed in the past, we only included OPSCC patients who died within 10 years of diagnosis. AAMRs were stratified by race, sex, and age at death and were presented per 100,000 person-years. Rate ratios (RRs) determined which groups had significantly different AAMRs, and Joinpoint regression calculated which groups had significant increases/decreases in annual AAMRs over time through annual percentage changes (APCs) and average APCs (AAPCs). We used 95% confidence intervals (CIs) to determine significant RRs, APCs, and AAPCs. Results: This study included 12,102 patients who died from first primary OPSCC from 1985-2016 with an AAMR of 1.16 per 100,000 person-years. AAMRs among males were 3.58 times higher than for females (RR = 3.58, 95% CI 3.43, 3.73). AAMRs among blacks were about 2 times higher than for whites (RR = 2.06, 95% CI 1.96, 2.16) but were about 60% lower for other race than whites (RR = 0.37, 95% CI 0.34, 0.42). From 1985-2009, AAMRs for first primary OPSCC decreased approximately 1.92% annually (APC = -1.92, 95% CI -2.27, -1.56) but remained stable from 2009-2016, which resulted in an average annual decrease of -1.31% from 1985-2016 (AAPC = -1.31, 95% CI -1.84, -0.78). When stratified by race or sex, all groups exhibited significant mortality rates decrease, however decrease was significantly greater among whites than blacks (white AAPC1985-2016 = -0.76; 95% CI -1.33, -0.17 vs black AAPC1985-2016 = -3.36; 95% CI -3.85, -2.87). AAMRs significantly decreased among 65+ year olds (AAPC = -0.88, 95% CI -1.63, -0.13), while AAMRs for 15-39 and 40-64-year olds exhibited non-significant decreases. Conclusions: While there has been significant decrease in oropharyngeal cancer mortality in the last three decades in the United States across age groups, races/ethnicity, and gender, there remained a significant mortality gap between blacks and whites, highlighting the persistent cancer-related disparity in the United States. Citation Format: Nosayaba Osazuwa-Peters, Matthew C Simpson, Sean T Massa, Eric Adjei Boakye, Kara M Christopher, Sai D Challapalli, Katherine M Polednik, Haley N Bray, Greg M Ward, Mark A Varvares. Oropharyngeal cancer incidence-based mortality trends in the United States, 1985-2016 [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D128.