(0753) Trends and Outcomes of Transoral Robotic Surgery in the Treatment of Advanced HPV-Positive Squamous Cell Carcinoma Antigen of the Oropharynx

Introduction: With improvements in dose reduction in intensity modulated radiotherapy (IMRT) in the management of p16+ SCCa of the oropharynx, there has been a reduction in primary surgical management of advanced disease. We hypothesize there has been a decrease in the utilization of primary surgery, but improvements in outcome with the use of TORS in treatment for advanced but resectable p16+ OP-SCCa.

Methods: This study is designed to analyze the trends in management and survival outcomes of p16+ T3-4, M0 oropharyngeal squamous cell carcinoma patients. Patients with p16+ T3-4 OP-SCCa diagnosed via AJCC 7th and 8th edition between 2010 and 2020 were selected from the National Cancer Database (NCDB), a hospital-based national database for analysis. The primary outcomes in this study were Treatment Modality Prevalence and Overall Survival. Chi-squared frequency analysis, Kaplan-Meier survival and multivariate regression models were used.

Results: A total of 39,160 cases met inclusion criteria. In 2010 21.1% of these patients were treated with primary surgery and adjuvant therapy; by 2020, this had decreased to 6.5% with a year-over-year linear decrease. Older, uninsured, those treated at community cancer programs, and those diagnosed in the South were more likely to undergo primary radiation. Time to initiation of treatment was significantly lower amongst those who received primary surgery (22.2 days vs 40.3, p< 0.01). Greater cN stage also conferred a decreased likelihood of performing primary surgery. Amongst those who received primary surgery, 74% received adjuvant radiation. Overall survival amongst those who underwent primary surgery and adjuvant radiation was significantly higher than those who underwent primary radiation without surgery (74.2% vs 63.5%, P< 0.01). This survival benefit persisted in COX multivariate regression (primary surgery with adjuvant radiation- HR 0.76 [0.71 – 0.81] when compared to primary radiation).

Conclusions: There appears to be a population of patients with locally advanced but resectable disease for whom primary TORS in addition to radiation may provide a survival benefit.