Volume Outcome Relationships of Oropharyngeal Cancer Patients Undergoing Transoral Robotic Surgery

Abstract

OBJECTIVES: We aim to demonstrate whether facility case volume is associated with (1) perioperative outcomes and (2) overall survival in patients with oropharyngeal cancer (OPC) undergoing transoral robotic surgery (TORS). METHODS: This is a retrospective cohort analysis of adults with OPC who underwent TORS between 2010 and 2017 using the National Cancer Database. Patients were stratified into high, mid, and low-volume facility groups based on facility TORS volume percentiles. Perioperative variables included 30- and 90-day mortality and positive margin rates. Baseline clinicopathologic variables and perioperative outcomes were compared using univariate testing. Multivariable analyses were carried out with logistic regression. Overall survival was evaluated by the Kaplan-Meier method with log-rank test as well as multivariable Cox proportional hazards models. Adjusted odds ratios (aOR) and hazard ratios (aHR) with 95% confidence intervals (CI) were created. RESULTS: 4294 patients were included. As facility volume increased, there were stepwise decreases in rates of positive margins, 30-day mortality, and 90-day mortality (p < 0.001, respectively). Low-and mid-volume facilities were associated with greater rates of 30- and 90-day mortality compared to high-volume facilities, adjusting for comorbidity and age. Mid- and high-volume facilities were independently associated with improved overall survival, adjusting for age, comorbidity, histologic type, and clinical T stage. CONCLUSION: Treatment at higher volume TORS facilities is associated with lower rates of perioperative mortality, lower positive margins, and improved long-term overall survival for patients with OPC. LEVEL OF EVIDENCE: N/A.