Association of Primary Treatment Modality for Advanced-Stage Oropharyngeal Squamous Cell Carcinoma With Survival Outcomes.

Importance: Definitive chemoradiotherapy and upfront surgical treatment are both accepted as the standard of care for advanced-stage oropharyngeal squamous cell carcinoma. However, the optimal primary treatment modality remains unclear. Objective: To evaluate the comparative effectiveness of definitive chemoradiotherapy and upfront surgical treatment for advanced-stage oropharyngeal cancer. Design, Setting, and Participants: This retrospective comparative effectiveness analysis used data from the population-based Taiwan Cancer Registry. Included patients were diagnosed with clinical stage III or IV oropharyngeal squamous cell carcinoma from 2007 to 2015 and were identified from the registry. Patients with T4b or N3 disease were excluded. Data were analyzed from June 2019 through December 2020. Interventions: Definitive chemoradiotherapy or upfront surgical treatment. Main Outcomes and Measures: The primary outcome was overall survival, for which data were available through December 31, 2018. Secondary outcomes were progression-free survival, locoregional recurrence-free survival, and distant metastasis-free survival. Results: Among 1180 patients, 694 patients (58.8%) were in the definitive chemoradiotherapy group and 486 patients (41.2%) were in the upfront surgical treatment group. The median (interquartile range) follow-up was 3.62 (1.63-5.47) years, and most patients were men (1052 [89.1%] men) with a primary tumor in the tonsils (712 patients [60.3%]), moderately differentiated histology (604 patients [51.2%]), clinical N2 disease (858 patients [72.7%]), and clinical stage IVA disease (938 patients [79.5%]). The mean (SD) age was 54.59 (10.35) years. Primary treatment with an upfront surgical procedure was associated with a decreased risk of death during the study period (hazard ratio [HR], 0.81; 95% CI, 0.69-0.97; P = .02). However, when adjusted for age, subsite, histological grade, and T and N classification, upfront surgical treatment was no longer associated with an increased risk of death during the study period (HR, 0.96; 95% CI, 0.80-1.16; P = .70). Progression-free survival was worse in the group receiving upfront surgical treatment than in the group receiving chemoradiotherapy (HR, 1.64; 95% CI, 1.09-2.46; P = .02), and this difference persisted after adjusting for other factors associated with prognosis (ie, age, tumor subsite, histological grade, and T and N classification) (HR, 1.72; 95% CI, 1.12-2.66; P = .01). Conclusions and Relevance: This study found that definitive chemoradiotherapy was associated with effectiveness that was comparable with that of upfront surgical treatment when adjusted for baseline factors associated with prognosis. These findings suggest that definitive chemoradiotherapy should be considered to avoid accumulating toxic effects associated with surgical treatment and chemoradiotherapy.