Abstract 722: Significance of p16 in site-specific HPV-positive and HPV-negative HNSCC

Abstract

Abstract Expression of p16INK4A (p16+ve) is highly correlated with human papilloma virus (HPV) infection in head and neck squamous cell carcinoma (HNSCC), however, p16-positivityis not limited to HPV-positive (HPV+ve) tumors and therefore, not a perfect surrogate for HPV. Also, p16+ve status has a strong relationship with survival and treatment outcomes in HNSCC, which is best documented for the oropharyngeal site (OP); non-OP sites such as the oral cavity (OC), larynx, and hypopharynx (HP) are understudied. The goal of this study was to evaluate p16 in the context of HPV and examine p16 survival outcomes in HPV+ve and HPV-negative (HPV-ve) site-specific HNSCC. The cohort of 80 primary HNSCC consisted of 10 HPV16+ve and 10 HPV16-ve cases each for four sites: OC, OP, larynx and HP. Expression of p16 was significantly different across sites (p<0.001), being more frequent in OP (65%) than in non-OP sites (13%). The frequency of p16 expression was different (p=0.031) between Caucasian Americans (CA, 38%) and African Americans (AA, 16%) similar to HPV (CA 65% vs AA 37%, p=0.013). p16+ve patients had improved survival for all sites combined and for the OP subgroup (similar to HPV+ve cases). However, subgroups defined by both HPV and p16, indicate that patients with p16-negative (-ve)/HPV-ve status had the worst survival for all sites combined as well as for OP. Cohorts with larger representations of non-OP sites examining multiple molecular markers will be key to deciphering and dissecting out p16's role as a useful prognostic indicator when assessed in combination with HPV status Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 722. doi:1538-7445.AM2012-722