Can Definitive Radiation Therapy Substitute Surgical Resection in Locally Advanced T3 or T4 Sinonasal Squamous Cell Carcinoma?

Purpose: This study aimed to compare oncologic outcomes between definitive radiation therapy (RT) and upfront surgical resection in patients with sinonasal squamous cell carcinoma (SCC).

Methods And Materials: Between 2008 and 2021, 155 patients with T1-4b, N0-3 sinonasal SCC were analyzed. The 3-year overall survival (OS), local progression-free survival (LPFS), and overall progression-free survival (PFS) were evaluated using the Kaplan Meier method and compared using a log-rank test. A pattern of regional neck lymph node (LN) failure and treatment-related toxicity profiles were investigated.

Results: A total of 63 and 92 patients underwent upfront RT (RT group) and surgical resection (Surgery group), respectively. The RT group included significantly more patients with T3-4 disease than the Surgery group (90.5% vs 39.1%, P < .001). The rates of 3-year OS, LPFS, and PFS in the RT and Surgery groups were 68.6% versus 81.7% (P = .073), 62.3% versus 73.8% (P = .187), and 47.4% versus 66.1% (P = .005), respectively. However, the corresponding rates in patients with T3-4 disease were 65.1% versus 64.8% (P = .794), 57.4% versus 56.8% (P = .351), and 43.2% versus 46.5% (P = .638), respectively, demonstrating no statistically significant differences between the 2 treatment modalities. Among the 133 N0 patients, regional neck LN progression was observed in 17 patients, and the most common sites of regional neck LN failure were ipsilateral levels Ib (9 patients) and II (7 patients). The 3-year neck node recurrence-free rate in cT1-3N0 patients was 93.5%, while that in cT4N0 patients was 81.1% (P = .025).

Conclusions: Upfront RT may be considered in selected patients with locally advanced sinonasal SCC, as we have demonstrated similar oncologic outcomes to those of surgery. Prophylactic neck treatment in T4 disease requires further investigation to evaluate its efficacy.