Patterns of distant metastases in HPV-positive head and neck squamous cell carcinoma.

6071 Background: Patients with HPV-positive head and neck squamous cell carcinoma (HPV+HNSCC) demonstrate favorable outcomes compared to HPV-negative SCC. Despite loco-regional control distant metastases (DM) can occur. The pattern of DM in HPV+HNSCC is not clearly defined. Methods: 109 patients with HPV+HNSCC underwent treatment at our institution from 2010-2012 (HPV status not identified prior to 2010). Recurrence time and metastatic sites were compared to patients with high risk HPV-negative/unknown SCC (HR HPV-/unk) and intermediate risk HPV-negative/unknown SCC (IR HPV-/unk) from 2006-2012. Results: Group 1: 109 patients with HPV+HNSCC (10 never achieved initial disease control). 7/109 (6.4%) developed DM. Median time to metastases was 11 months (range 7-41 months, mean 16 months). Median follow up from diagnosis was 18 months. Predominant sites of metastases were lung (6), liver (1), bone (1), and brain (1). 5/7 patients with DM (out of 65 patients with a tobacco history and 44 without) had prior or...