Background

Human papillomavirus (HPV)-positive oropharyngeal cancer (HPV-OPC) is distinct from HPV-unassociated head and neck cancer. However, whether risk factors for HPV-positive oropharyngeal and nonoropharyngeal squamous cell cancer are the same is unclear.

Methods

Incident cases of HPV-positive head and neck cell cancer and matched non-cancer controls were enrolled in a multi-institutional, prospective study examining risk factors, biomarkers, and survival.

Results

HPV-nonOPC (n = 20) were more likely to be ever smokers than controls (n = 80, OR 3.49, 95%CI 1.11-10.9) and HPV-OPC (n = 185, OR 3.28, 95%CI 1.10-10.2). Compared with HPV-OPC, HPV-nonOPC were less likely to have had over 3 oral sexual partners (OR 0.29, 95%CI 0.06-0.9), more likely to have multimorbidity (OR 3.30, 95%CI 1.04-10.5), and less likely to have antibodies to HPV16 E6 (90% vs 28%, OR 0.05, 95%CI 0.02-0.2). HPV-nonOPC had worse 4-year OS (77% vs 96%, P = .001) and RFS (69% vs 94%, P < .001) than HPV-OPC.

Conclusions

HPV-positive nonoropharyngeal are distinct from HPV-positive oropharyngeal cancers.

BACKGROUND:The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing among older adults. It is unknown whether these trends can be explained by human papillomavirus (HPV) and whether HPV-related tumors remain associated with an improved prognosis among older patients. METHODS:In a retrospective study of OPSCCs diagnosed from 1995 to 2013 at 2 National Comprehensive Cancer Network-designated cancer centers, p16 immunohistochemistry and in situ hybridization (ISH) for HPV-16, high-risk DNA, and/or E6/E7 RNA were performed. The median age at diagnosis was compared by p16 and ISH tumor status. Trends in age were analyzed with nonparametric trends. Survival was analyzed with the Kaplan-Meier method and Cox proportional hazards models. RESULTS:Among 239 patients, 144 (60%) were p16-positive. During 1998-2013, the median age increased among p16-positive patients (Ptrend = .01) but not among p16-negative patients (Ptrend = .71). The median age of p16-positive patients increased from 53 years (interquartile range [IQR] in 1995-2000, 45-65 years) to 58 years (IQR for 2001-2013, 53-64 years). Among patients ≥ 65 years old, the proportion of OPSCCs that were p16-positive increased from 41% during 1995-2000 to 75% during 2007-2013 (Ptrend = .04). Among all age groups, including older patients, a p16-positive tumor status conferred improved overall survival in comparison with a p16-negative status. CONCLUSIONS:The median age at diagnosis for HPV-related OPSCC is increasing as the proportion of OPSCCs caused by HPV rises among older adults. The favorable survival conferred by an HPV-positive tumor status persists in older adults. Cancer 2018;124:2993-9. © 2018 American Cancer Society.