The role of concomitant chemoradiotherapy versus radiation alone in T1-3N0 HPV-positive and HPV-negative oropharyngeal squamous cell carcinoma

Objective: To evaluate the role of curative intent concurrent chemoradiation (CCRT) vs radiation (RT) alone for T1-T3N0 HPV-positive and HPV-negative oropharyngeal squamous cell cancer (OPSCC). Methods: The NCDB was queried for patients diagnosed between 2010 and 2017 with cT1-3N0M0 OPSCC treated with definitive RT or CCRT. Univariable analysis (UVA) and multivariable analysis (MVA) Cox regression analysis was performed with OS as the endpoint. Propensity score matching (PSM) 1:1 was performed. Interaction test to assess heterogeneity of treatment effect. Results: A total of 2830 patients were queried. On MVA, CCRT was associated with improved OS for T3N0 tumors (HR 0.49; 95% CI 0.39-0.63) but not for T1N0 (HR 1.43; 95% CI 0.99-2.07) and T2N0 (HR 0.92; 95% CI 0.75-1.13). For T3 patients, CCRT improved OS for HPV-negative (HR 0.43; 95% CI 0.31-0.59) and HPV-positive tumors (HR 0.39; 95% CI 0.25-0.61). After PSM, CCRT was not statistically different to RT for patients with T12N0 HPV-negative tumors (HR 1.10; 95% CI 0.85-1.43; p = 0.48) and T1-2N0 HPV-positive tumors (HR 1.15; 95% CI 0.79-1.68; p = 0.45). After PSM, CCRT improved OS compared to RT alone for patients with T3N0 HPVnegative (HR 0.43; 95% CI 0.31-0.59; p < 0.01) and HPV-positive tumors (HR 0.39; 95 %CI 0.25-0.61; p < 0.01). Conclusions: CCRT is associated with improved OS in HPV-positive and HPV-negative T3N0 OPSCC. RT alone vs. CCRT demonstrated similar OS for T1-T2N0 OPSCC for both HPV negative and HPV positive tumors.