HN 03-03INCREASING PREVALENCE OF HPV-POSITIVE TUMOR STATUS AMONG OLDER ADULTS WITH OROPHARYNGEAL CANCER, 1995-2013

27. HPV and oropharynx / Head and neck cancer
M. Benson 1, E. Rettig 1, W. Westra 2, S. Wang 3, A. Van Zante 4, Y. Zhang 2, L. Yin 5, W. Ryan 3, P. Ha 3, A. Wentz 5, W. Koch 1, J. Richmon 1, D. Eisele 1, G. D'souza 5, C. Fakhry 1.
1Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins University (United States), 2Department of Pathology, Johns Hopkins University (United States), 3Head and Neck Surgery, Department of Otolaryngology, University of California San Francisco (United States), 4Department of Pathology, University of California San Francisco (United States), 5Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health (United States)

Background / Objectives

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing among elderly adults in the United States [1]. The purpose of this study was to examine whether this recent rise in OPSCC among older age cohorts is due to increasing prevalence of human papillomavirus (HPV)-positive tumor status among elderly adults with OPSCC, and to determine whether HPV-positive tumor status continues to confer improved survival among older age cohorts.


Methods

This was a retrospective, multi-institutional study of OPSCCs diagnosed from 1995-2013. HPV tumor status was determined using immunohistochemistry for p16 overexpression and in-situ hybridization for HPV16 DNA and high-risk E6/E7 mRNA. Patient age at diagnosis, HPV tumor status, and calendar periods were compared. Survival was analyzed using Kaplan-Meier method and Cox Proportional Hazards models.


Results

There were 240 patients with OPSCC included in this analysis, of which 124 (52%) were HPV-positive. Between 1995-2013, median age increased among HPV-positive OPSCCs (ptrend=0.05), but not among HPV-negative OPSCCs (1995-2013 ptrend=0.86). The median age of HPV-positive OPSCC patients increased from 43.5 years (interquartile range [IQR] 52-60.5) in 1995-2000 to 52 years (IQR 56-53) in 2007-2013. Among patients ≥65 years old, the proportion of OPSCCs that were HPV-positive increased from 29% (5/17) in 1995-2000 to 52% (11/21) in 2001-2006, then 60% (12/20) in 2007-2013 (ptrend=0.07). This was similar to the increase noted among patients 55-64 years old (24% [5/12] in 1995-2000 to 58% [18/31] 2007-2013, ptrend=0.03). Among older age cohorts, HPV-positive tumor status was associated with significantly improved overall survival compared with HPV-negative tumor status (>65 year old:  HR=0.56, 95% CI=0.29-1.10; >60 year old HR=0.37 95%CI=0.20-0.67). The association of HPV tumor status with improved overall survival after OPSCC diagnosis was not significantly attenuated with increasing patient age (p=0.56 for interaction of age and HPV status).


Conclusion

The median age at diagnosis of HPV-OPSCC is increasing as the proportion of OPSCCs caused by HPV rises among older age cohorts. The favorable survival conferred by HPV-positive tumor status is not modified by age.


References

[1] Zumsteg Z S, Cook-Wiens G, Yoshida E, Shiao S L, Lee N Y, Mita A, Jeon C, Goodman M T and Ho A S. “Incidence of Oropharyngeal Cancer Among Elderly Patients in the United States.” JAMA Oncol. 2016;2(12):1617-1623.