Differences in Survival With Surgery and Postoperative Radiotherapy Compared With Definitive Chemoradiotherapy for Oral Cavity Cancer: A National Cancer Database Analysis.

Importance: Because locally advanced oral cavity squamous cell carcinoma (OCSCC) is often treated with surgery followed by postoperative radiotherapy (S+PORT), the effectiveness of organ preservation with concurrent chemoradiotherapy (CRT) remains unclear. Objective: To compare the differences in survival between patients with locally advanced OCSCC treated with S+PORT or CRT. Design, Setting, and Participants: Using the National Cancer Database, this study compared 6900 patients with stage III to IVA OCSCC treated with S+PORT and CRT from 2004 through 2012 at academic and community-based cancer clinics. Comparisons were made using Kaplan-Meier methods and Cox proportional hazards regression models using the entire cohort and a propensity score-matched cohort of 2286 patients. Main Outcomes and Measures: Overall survival (OS). Results: Of the 6900 study patients, 4809 received S+PORT (3080 male [64.0%] and 1792 [36.0%] female) and 2091 received CRT (1453 male [69.5%] and 638 [30.5%] female). Median follow-up for the entire group was 23.0 months overall but was shorter for patients receiving CRT (17.3-month) vs S+PORT (25.6 months). Patients receiving CRT were more likely to be older than 60 years, treated before 2007, live within 10 miles of the treating facility, treated at nonacademic centers, have more comorbidities, have T3 to T4a tumors, and have N2a to N2c nodal disease. Propensity score matching identified cohorts of patients with similar clinical variables. S+PORT was associated with improved survival among all patients (3-year OS: 53.9% for S+PORT vs 37.8% for CRT; difference = 16.1%; 95% CI, 13.6%-18.6%) and in the propensity score-matched cohort (3-year OS: 51.8% for S+PORT vs 39.3% for CRT; difference = 11.9%; 95% CI, 7.8%-16.0%). S+PORT was associated with improved survival among patients with T3 to T4a tumors (3-year OS: 49.7% for S+PORT vs 36.0% for CRT; difference = 16.1%; 95% CI, 13.6%-18.6%) but was not associated with improved survival among patients with T1 to T2 tumors (3-year OS: 59.1% for S+PORT vs 53.5% for CRT; difference = 5.6%; 95% CI, -3.1% to 14.3%). Conclusions and Relevance: Compared with CRT, S+PORT was associated with improved survival for locally advanced OCSCCs, especially in T3 to T4a disease. These data support the use of surgery as the initial treatment modality for operable OCSCCs.