Windon MJ, et al. - Authors evaluated whether the increasing incidence of oropharyngeal squamous cell carcinoma (OPSCC) among older adults could be explained by human papillomavirus (HPV) and if HPV-related tumors are still linked to an improved prognosis in older patients. For HPV-related OPSCC, the median age at diagnosis is increasing as the percentage of OPSCCs caused by HPV rises among older adults. In older adults, the favorable survival conferred by an HPV-positive tumor status remains.

Methods

• Experts in a retrospective study of OPSCCs diagnosed from 1995 to 2013 at two National Comprehensive Cancer Network–designated cancer centers, performed p16 immunohistochemistry and in situ hybridization (ISH) for HPV-16, high-risk DNA, and/or E6/E7 RNA.
• They compared the median age at diagnosis by p16 and ISH tumor status, and analyzed the trends in age with nonparametric trends.
• With the Kaplan-Meier method and Cox proportional hazards models, survival was analyzed.

Results

• As per data, from 239 patients, 144 (60%) were p16-positive.
• The median age increased among p16-positive patients (P_trend=.01) but not among p16-negative patients (P_trend=.71) from 1998-2013.
• 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).
• The proportion of OPSCCs that were p16-positive increased from 41% during 1995-2000 to 75% during 2007-2013, among patients ≥ 65 years old (P_trend=.04).
• Compared with a p16-negative status, a p16-positive tumor status conferred improved overall survival across all age groups, including older patients.