Utilization of Transoral Robotic Surgery in Patients With Oropharyngeal Squamous Cell Carcinoma and Its Impact on Survival and Use of Adjuvant Therapy Compared to Treatment With Definitive Radiation Therapy

Abstract

To assess trends in Transoral Robotic Surgery (TORS) utilization and its impact on overall survival (OS) and use of adjuvant therapy compared to treatment with definitive radiation therapy (RT) for patients with oropharyngeal squamous cell carcinoma (OPSCC). We identified all T1-T2, N0-N2b OPSCC patients who received TORS or definitive RT for the upfront management of OPSCC from the National Cancer Database registry between 2010-2014. Trends in TORS use over time and adjuvant chemotherapy or RT use are reported as percentages. Propensity score matching was performed to account for baseline differences between covariates in the TORS versus definitive RT group. OS was measured from time of diagnosis until death or last follow up and the Kaplan Meier method was used to estimate OS. A multivariable logistic regression was performed to assess the impact of TORS on adjuvant chemotherapy and radiation therapy use. Adjustment variables included in the analysis were clinical T and N-stage, oropharynx subsite, overall stage, age, sex, race, median income, facility type, Charlson comorbidity score, diagnosis year, HPV status, and TORS use. The Wilcoxon rank sum test was used for median comparisons between groups, and the χ2 test was used to compare categorical variables. A total of 17,150 patients met inclusion criteria. Of these, 2680 (15.6%) received TORS and 14,470 (84.4%) underwent definitive RT. Median follow-up was 31 months. The use of TORS increased steadily from 2010 (13%) to 2014 (27%). Covariates associated with increased TORS use include tonsil subsite, early T stage, higher median income, and younger age. Eighty-two percent of patients treated with RT received chemotherapy, compared to 33% of patients treated with TORS (χ2, P < .001). After adjustment, TORS was still associated with decreased use of chemotherapy compared to definitive RT (Adjusted OR: 0.09, 95% CI 0.08-0.11, P < .001). Sixty-one percent of patients treated with TORS were also treated with adjuvant radiation therapy to a median dose of 60 Gy (25th-75th percentile range: 60-66 Gy, IQR 6 Gy). After propensity score matching (n = 845 in each arm), 2-year OS was 93.4% versus 93.0% in the TORS and definitive RT cohort, respectively (HR: 0.86, 95% CI 0.71-1.04; log-rank, P = .10). After propensity score matching, TORS use continued to be associated with decreased chemotherapy use (adjusted OR: 0.11, 95% CI 0.09-0.13, P < .001). Median RT dose was 69.96 Gy in patients treated with definitive RT versus 60 Gy for those treated with TORS (P < .001). Our findings demonstrate that TORS did not impact OS compared to treatment with definitive RT. We also found an association between TORS use and decreased utilization of chemotherapy as well as the ability to deliver lower RT doses. Prospective trials to compare quality of life and patient reported outcomes in patients treated with and without TORS are needed.