Treatment outcomes in veterans with HPV-positive head and neck cancer.

ABSTRACT

OBJECTIVES: Head and neck squamous cell carcinoma (HNSCC) caused by the human papilloma virus (HPV) has an improved prognosis relative to HPV-negative tumors. Patients with HPV-positive disease may benefit from different treatment modalities in order to optimize survival and quality of life. We sought to investigate HPV-positive HNSCC within the military veteran population, and analyze the role of treatment modality in outcomes of patients with HPV-positive and HPV-negative tumors. METHODS: Patients diagnosed with HNSCC between January 1, 2010 and December 31, 2014 at one regional veterans health center were retrospectively examined. Pathologic specimens underwent testing for HPV subtype and p16 expression. Demographic and clinical factors, including treatment modality, were analyzed for their impact on the primary outcome of overall survival. RESULTS: There were 209 patients with primary tumor sites including larynx (25.4%), oral tongue (19.6%), oral cavity (13.4%), oropharynx (17.2%), tonsil (17.2%), unknown primary (2.9%), nasopharynx (1.9%), and multiple sites (2.4%). Patients had HPV-positive (n=82, 39.2%), HPV-negative (n=89, 42.6%) or unknown HPV status (n=38, 18.2%). Primary treatment modalities were chemoradiation (n=124, 59.3%), surgery (n=39, 18.7%), radiation therapy (n=37, 17.7%), or no treatment (n=9, 4.3%). Survival analysis with Cox proportional hazards model demonstrated significant associations with T classification (T4 3.61, P=0.005), N classification (N3 3.52, P=0.0159), M classification (M1 2.8, P=0.0209), and HPV status (HPV-positive 0.43, P=0.0185), but no relation with primary treatment modality (primary surgery vs. primary chemoradiation 1.01, P=0.9718). CONCLUSION: HPV-positive HNSCC in the veteran population has a significantly improved prognosis relative to similarly staged patients with HPV-negative disease. This study demonstrates that the primary treatment modality - chemoradiation, radiation therapy, or surgery - does not impact overall survival among veterans with HPV-positive HNSCC.