Abstract PO-232: Univariate and multivariate prognostic factors for overall survival among oropharyngeal cancer patients with known HPV/p16 status
Authors: Nittala Mary R. , Mundra Eswar K. , Albert Ashley , Woods William C. , Smith Maria L. , Hamilton Robert D. , Jackson Lana , Jefferson Gina , Packianathan Satyaseelan , Bhanat Eldrin , Manucha Varsha , Vijayakumar Srinivasan 
Published: December 2020

Abstract
Purpose: To assess the prognostic significance of tumor HPV/p16 status among oropharyngeal squamous-cell carcinoma (SCC) patients. Methods: A retrospective analysis of 80 patients diagnosed with oropharyngeal SCC between 2008 and 2018 at an academic medical center with known HPV/p16 status was performed. Pearson’s Chi-squared test was used to compare the proportional differences between the known tumor HPV status among positive and negative p16 staining groups. Kaplan- Meier analysis was used to estimate overall survival [OS] and local control [LC] between the HPV groups stratified by risk and compared using the log-rank test. Uni and multi-variable Cox hazard regression analyses were used to compare the risk of death among patients with HPV- positive and HPV- negative cancer. The SPSS v.24.0 was used for all statistical analyses. Results: Our patient cohort included 37.5% HPV- positive and 62.5% HPV-negative (median age, 61 y; range 45-86 y) patients. Patient groups were classified on the basis of risk factors: HPV/p16 status, pack-years [py] of tobacco smoking, and tumor stage into low (p16+, ≤ 10 py), intermediate (p16+, &gt; 10 py/p16-, &lt; 10 py), and high risk (p16-, &gt; 10 py/ any T4), accounting for 36.7%, 36.7% and 26.7% of HPV-positive and 0%, 20% and 40% of HPV-negative patients, respectively (p=0.000). The median follow-up duration for this cohort was 34 months (range 0 to 154 months). The low risk HPV-positive group had better 5-year OS rates (87.5%, vs. 59.5% and 27.2%) compared to intermediate and high risk groups (p=0.003 by the log-rank test). After adjustment for gender, age, race, income level, distance travelled, tobacco exposure, alcohol history, tumor stage, and treatment modality, this group had a 63% reduction in the risk of death (hazard ratio, 0.37; 95% CI, 0.18-0.77; p= 0.008). Insurance and BMI was associated with a 71% reduction (hazard ratio, 0.29; 95% CI, 0.97-0.89; p=0.032), and a 49% reduction in the risk of death (hazard ratio, 0.51; 95% CI, 0.37-0.71; p=0.000), respectively. In terms of LC, the low risk HPV-positive patients had better 3-year rates 70.1%, vs. 55.7% and 39.9% compared to the intermediate and, high risk groups (p=0.379). Conclusion: Tumor HPV/p16 status may be an independent prognostic factor along with insurance status and BMI for overall survival among oropharyngeal SCC patients.
Citation Format: Mary R. Nittala, Eswar K. Mundra, Ashley Albert, William C. Woods, Maria L. Smith, Robert D. Hamilton, Lana Jackson, Gina Jefferson, Satyaseelan Packianathan, Eldrin Bhanat, Varsha Manucha, Srinivasan Vijayakumar. Univariate and multivariate prognostic factors for overall survival among oropharyngeal cancer patients with known HPV/p16 status [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-232.