Abstract PR004: Differential gene expression analysis comparing Black and White patients with HPV-positive oropharyngeal squamous cell carcinoma reveals suppressed immune response and higher rates P16/HPV DNA discordance in Black patients
Authors: Watts Tammara L. , Gonzalez Katerine , Shen Xiangfeng , Rogers Layne , Osazuwa-Peters Nosa , Jefferson Gina D. , Clement Cecilia G. , Range Danielle , Kahmke Russel R , Lee Walter T , Rocke Daniel J. , Cannon Trinitia Y , Mowery Yvonne , Owzar Kouros 
Published: September 2024

Abstract
Background-Human papilloma virus (HPV-positive (+)) oropharynx cancer (OPC) are a distinct neoplastic entity associated with a significant survival advantage compared to HPV- OPCs. The survival advantage is so great that the presence of regional cervical lymph node metastasis is no longer considered an advanced stage III/IV cancer. The survival advantage associated with HPV+ OPC is not the same for Black patients compared to all other races and emerging data now suggests Black patients with HPV+ OPC have survival outcomes similar to White patients with HPV- OPC. We conducted a differential gene expression analysis and high-risk HPV serotyping comparing genomic difference between treatment naïve Black and White patients with HPV+ OPC. Methods: Surgical samples were obtained from Duke, the University of Texas Medical Branch, and the University of Mississippi, through an IRB approved protocol. HPV status determined by p16 immunohistochemistry (IHC). We performed digital spatial profiling and conducted a differential gene expression analysis in 14 Black and 13 White patients using the Nanostring™ Whole Transcriptome Atlas. Morphology markers included CD45, PANCK, and alpha SMA to label lymphocytes, epithelium, and stroma, respectively. A component of the bioinformatics pipeline included conducing a KEGG pathway analysis using pre-ranked test statistics from self-reported Black and White patients HPV+ OPC. The presence of high-risk oncogenic HPV was determined in parallel by RT-PCR (Creative Biogene). P16, CD68 and CD3 expression was measured by IHC using standard techniques. Results: There was a significant decrease in antigen processing and presentation and T-cell receptor signaling pathways in CD45+ lymphocytes (p&lt;0.0002) and B-Cell receptor and chemokine signaling pathways in PANCK+ tumor epithelial cells (p&lt;0.03) in Black patients compared to White patients with HPV+ OPC. There was a significant difference in p16 expression and the absence of HPV DNA in Black patients compared to White patients (p&lt;0.017). 32% of Black patients with p16+ OPC were HPV DNA negative. There was no p16/HPV16 DNA discordance observed in the White patient cohort. Three patients were co-infected with other carcinogenic HPV serotypes (45, 51, and 59) in addition to HPV16 (two Black and one White). CD68 expression, associated with M1-like anti-tumor macrophages, was significantly decreased in Black patients with p16+/HPV16+ OPC, compared to White patients (p&lt;0.017), suggesting alterations in tumor immune response may be important in cancer disparities. Conclusion: The favorable prognosis associated with HPV+ OPC, including recruitment in currently ongoing radiation de-escalation clinical trials cannot be widely applied to all patients with HPV+ OPC and studies addressing racial disparities, HPV/p16 discordance, and predictors of poor response represent a significant health equity gap in the field of OPC disparities.
Citation Format: Tammara L. Watts, Katerine Gonzalez, Xiangfeng Shen, Layne Rogers, Nosa Osazuwa-Peters, Gina D. Jefferson, Cecilia G. Clement, Danielle Range, Russel R Kahmke, Walter T Lee, Daniel J. Rocke, Trinitia Y Cannon, Yvonne Mowery, Kouros Owzar. Differential gene expression analysis comparing Black and White patients with HPV-positive oropharyngeal squamous cell carcinoma reveals suppressed immune response and higher rates P16/HPV DNA discordance in Black patients [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr PR004.