(0675) Long-Term Survival and Oncologic Outcomes in HPV-Associated Oropharyngeal Squamous Cell Carcinoma Following Transoral Robotic Surgery

Introduction: The transoral robotic surgery (TORS) approach for head and neck cancers was FDA-approved in 2009; there is a paucity of literature on long-term outcomes of this treatment for human papilloma virus-associated oropharyngeal squamous cell carcinoma (HPV+ OPSCC).

Methods: In this retrospective cohort study, patients with HPV+ OPSCC who underwent TORS from March 1, 2007 to August 30, 2013 at a single academic medical center were included. The primary outcome was overall survival. Secondary outcomes included disease-free survival, recurrence, diagnosis of second primary cancers, and major adverse events. RStudio was used for statistical analyses.

Results: 256 patients were included. Patients had ENT follow-up for a median 62.6 months (IQR 46-98) and overall follow-up of 116.7 months (IQR 60-137). Kaplan-Meier estimates of overall survival (OS) at 5 and 10 years were 87.3% and 81.5% respectively. No significant difference in OS was observed based on second primary incidence or treatment type (surgery vs surgery + adjuvant treatment). Kaplan-Meier estimates of disease-free survival (DFS) at 5 and 10 years were 92% and 85.9% respectively. At 2-years, DFS was significantly lower in patients treated with surgery alone compared to treatment with surgery and adjuvant therapies (83.6% vs 91.6%, p-value = 0.04). During the surveillance period 34 (13.3%) patients had recurrent OPSCC, 11 (4.3%) had second primary head and neck tumors, and an additional 26 (10.2%) had second primary tumors of other sites. Overall, second primary incidence was 14.8% with a median time to diagnosis of 61.2 months (IQR 11-89). Of the total, 37 patients (14%) were diagnosed with pneumonia, 16 (6%) with a cerebrovascular accident, and 16 (6%) with a myocardial infarction.

Conclusions: DFS is significantly lower for 2 years post-TORS in patients treated with surgery alone versus those treated with surgery and adjuvant therapy; this DFS difference is not significant after the 2-year timepoint. There was a notable rate of second primary incidence, although this was not significant to overall survival.