3641 - Outcomes of Surgery, Concurrent Chemoradiotherapy, and Definitive Radiotherapy in Early-Stage Oral Cancer: A National Database Analysis

Purpose/Objective(s):

The National Comprehensive Cancer Network (NCCN) guidelines recommend surgery or definitive radiotherapy (RT) as first-line treatment for patients with clinical T1–2N0M0 oral cancer. However, prior studies have suggested superior outcomes with surgery compared with definitive RT alone. This study compared survival and disease control outcomes between surgery and RT and further evaluated whether concurrent chemoradiotherapy (CCRT) improves outcomes compared with RT alone and achieves outcomes comparable to surgery.

Materials/Methods:

This retrospective population-based study analyzed data from the Taiwan Cancer Registry between 2011 and 2021. Patients with clinical T1–2N0 oral squamous cell carcinoma treated with surgery or definitive RT with or without chemotherapy were included. Due to substantial treatment imbalance (98.2% surgery vs. 1.8% RT), a 1:6 case-matching strategy was applied, yielding a final matched cohort of 1,673 patients. Overall survival (OS), disease-free survival (DFS), and locoregional recurrence (LRR) were analyzed. Multivariable regression and stratified analyses were performed to adjust for potential confounders and to compare outcomes across treatment modalities. The RT group was further subdivided into definitive RT alone and CCRT for comparative analyses with surgery.

Results:

Among the 1,673 matched patients, 434 (25.94%) had T1 disease and 1,239 (74.06%) had T2 disease. Surgery was associated with significantly improved 5-year OS compared with RT (79.4% vs. 47.3%, P < 0.001), as well as superior DFS and lower LRR rates (15.9% vs. 24.4%, P < 0.001). On multivariable analysis, surgery independently predicted improved OS (adjusted hazard ratio [aHR], 3.54) and reduced LRR (aHR, 2.00). Stratified analyses consistently showed superior OS with surgery across all subgroups. However, comparable locoregional control was observed in patients aged 65–74 years, those aged =75 years, females, and patients with clinical T1 disease.

Within the RT cohort, CCRT was associated with improved outcomes compared with definitive RT alone. Although surgery remained associated with superior OS compared with CCRT (aHR, 1.75), no significant differences were observed between surgery and CCRT in 5-year DFS or LRR. Notably, multivariable analysis showed that CCRT achieved OS comparable to surgery in patients aged 65–74 years and those with cT1 disease and demonstrated comparable DFS and locoregional control across all subgroups.

Conclusion:

Surgery was associated with superior survival and locoregional control compared with definitive RT in patients with early-stage oral cancer. Although surgery remained associated with better OS than CCRT, CCRT achieved comparable DFS and locoregional control. For patients who are not suitable surgical candidates, CCRT represents a reasonable alternative and may provide improved outcomes compared with definitive RT alone.