2026 Proffered Presentations
S156: SINONASAL SQUAMOUS CELL CARCINOMA: A POPULATION-BASED ANALYSIS OF PROGNOSTIC FACTORS AND CONTEMPORARY SURVIVAL OUTCOMES
Emma Tam, BA; Emma Anisman, BA; Elliott Sina, BA; Elina M Toskala, MD, PhD, MBA; Mindy R Rabinowitz, MD; Marc R Rosen, MD; Gurston G Nyquist, MD; Thomas Jefferson University
Background: Sinonasal squamous cell carcinoma (SNSCC) represents a rare but challenging malignancy with limited contemporary survival data. Prior SEER analyses included cases only through 2015, leaving a gap in more recent prognostic benchmarks. We conducted an updated population-based analysis using the SEER database to identify key predictors of disease-specific survival and provide updated prognostic benchmarks.
Methods: From 16,372 patients with sinonasal malignancies diagnosed between 2000-2022, we identified 6,159 patients with histologically confirmed squamous cell carcinoma using ICD-O-3 morphology codes 8070-8075. Kaplan-Meier analysis calculated disease-specific survival across demographic and clinical variables, with multivariable Cox regression modeling used to identify independent prognostic factors.
Results: Tumor anatomic location was the most powerful predictor of outcome. Patients with primary nasal cavity tumors demonstrated excellent 5-year survival at 80.1%, while those with primary paranasal sinus tumors had markedly worse survival: maxillary sinus 42.8%, ethmoid sinus 40.9%, frontal sinus 52.6%, and sphenoid sinus 48.1%. Compared with primary nasal cavity tumors, mortality risk was higher for tumors arising in the maxillary sinus (HR=3.51, 95% CI: 3.15-3.91), ethmoid sinus (HR=3.34, 95% CI: 2.97-3.76), frontal sinus (HR=2.64, 95% CI: 2.18-3.20), sphenoid sinus (HR=2.62, 95% CI: 2.01-3.41), overlapping lesions of accessory sinuses (HR=3.17, 95% CI: 2.75-3.65), and accessory sinus (not otherwise specified) (HR=2.87, 95% CI: 2.50-3.29) (all p<0.001).
Higher tumor grade was associated with progressively worse survival. Compared to well-differentiated Grade I tumors, moderately differentiated Grade II lesions carried 45% higher mortality risk (HR=1.45, 95% CI: 1.28-1.65), while poorly differentiated Grade III tumors increased risk by 72% (HR=1.72, 95% CI: 1.51-1.96) (both p<0.001). Undifferentiated/anaplastic Grade IV tumors showed a nonsignificant trend towards worse survival (HR 1.42, 95% CI: 0.96–2.12, p=0.083). Advanced age also predicted worse outcomes, with patients 75 years and older experiencing 36% higher mortality compared to those under 50 years (HR=1.36, 95% CI: 1.16-1.60, p<0.001).
Treatment factors demonstrated significant prognostic impact. Surgical resection of the primary site as part of the initial course of therapy was associated with the most substantial survival benefit, reducing mortality risk by 57% compared to non-surgical management (HR=0.43, 95% CI: 0.39-0.47, p<0.001). External beam radiotherapy offered more modest benefit, reducing mortality risk by 11% (HR=0.89, 95% CI: 0.81-0.98, p=0.014). Notably, demographic factors including sex, race, rural vs urban residential location, and median income did not independently influence survival when controlling for clinical variables, despite race demonstrating significance on univariate analysis.
Conclusions: To our knowledge, this represents the most up-to-date survival analysis of SNSCC, using SEER data through 2022. This comprehensive analysis reveals that anatomic subsite dominates prognosis in sinonasal squamous cell carcinoma, with nasal cavity tumors achieving nearly twice the 5-year survival of paranasal sinus locations. Our findings show that surgical resection of the primary site was most strongly associated with improved survival, emphasizing the critical role of subsite in patient counseling and treatment planning. Unlike many other cancers, demographic and socioeconomic disparities appear less influential than tumor biology and treatment factors in determining outcomes for this rare malignancy.