Abstract C92: Systematic review of the literature confirms disparities in the prevalence of HPV-positive oropharynx cancer between African Americans and U.S. whites
Authors: Ragin Camille Ragin , Jones Gieira , Shoyele Olubunmi , Esan Michael , Gibbs Denise , Liu Jeffery , Gathere Samuel , Taioli Emanuela 
Published: May 2015

Abstract
Background: Head and neck cancer (HNC) includes cancers of the oral cavity, larynx and pharynx (which include the oropharynx) and is the sixth most common cancer in the world. Approximately 52,610 new cases and 11,500 deaths from HNC were expected in the United States in 2012. Tobacco and alcohol use are the primary risk factors for developing HNC and human papillomavirus (HPV) is etiologically linked to the majority of oropharynx cancers. HPV-positive oropharyngeal cancer patients have been shown to have improved survival rates compared to HPV-negative patients. It has been suggested that the noted disparity in oropharyngeal cancer survival between African-Americans and Caucasians is due to a lower prevalence of HPV-positive oropharynx tumors in African-American patients. To date this documentation has been limited to only a few small studies.
Purpose: In this study we have conducted a systematic review and meta-analysis of the literature to confirm whether a racial disparity in the prevalence of HPV-positive tumors exists between African Americans and US Whites.
Results: All articles conducted in the United States that report HPV prevalence by direct evaluation of HNC tissues were included in this study. Studies that evaluated p16 status or HPV serological status as a surrogate marker for HPV-positive HNC were not included. Ninety-four studies were identified which included data for 9,144 cases. There were 15 studies (278 cases) that reported HPV status of HNC from African American patients while 24 studies (2,853 cases) reported HPV status of HNC from White patients. For all other studies race-specific prevalence of HPV was indistinguishable. Preliminary analyses show that overall for African Americans the meta prevalence of HPV-positive HNC was 17.8%, (95% Confidence interval[CI], 13.4-23.3). No heterogeneity was observed between studies (Q-test p-value = 0.172, I-squared = 26%, 0-61). Stratification of these data according to oropharynx and non-oropharynx sub-sites did not result in significant differences (meta prevalence: oropharynx = 18.8%, 95% CI, 10.2-32.1; non-oropharynx = 17.8%, 95% CI, 10.6-28.3). There was also no evidence of heterogeneity between the studies and no evidence of publication bias was observed (Eggers-test p-value, 0.224). In contrast the meta prevalence of HPV-positive HNC in US Whites was 42.7%, 95% CI, 34.7-51.1 but there was large heterogeneity between the studies (Q-test p-value &lt;0.0001, I-squared &gt; 90%). Stratification of the studies between oropharynx and non-oropharynx sub-sites did not resolve the heterogeneity between the studies. There was also no evidence of publication bias (Eggers-test p-value, 0.993). Further investigations are ongoing.
Conclusions: Our preliminary findings show that disparity HPV-positive oropharyngeal cancers exist between African Americans and US Whites. The lower prevalence of HPV in African Americans diagnosed with oropharyngeal cancer may explain in part the poor outcomes observed in these populations. Further investigations of possible reasons for this disparity are needed.
Citation Format: Camille Ragin Ragin, Gieira Jones, Olubunmi Shoyele, Michael Esan, Denise Gibbs, Jeffery Liu, Samuel Gathere, Emanuela Taioli. Systematic review of the literature confirms disparities in the prevalence of HPV-positive oropharynx cancer between African Americans and U.S. whites. [abstract]. In: Proceedings of the Sixth AACR Conference: The Science of Cancer Health Disparities; Dec 6–9, 2013; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2014;23(11 Suppl):Abstract nr C92. doi:10.1158/1538-7755.DISP13-C92