Occult Nodal Involvement in Sinonasal Squamous Cell Carcinoma.

BackgroundSinonasal squamous cell carcinoma (SNSCC) is an aggressive subtype of sinonasal cancer. While elective neck dissection (END) is not typically recommended for SNSCC, occult nodal involvement (ONI) may be present. We therefore sought to evaluate the incidence, associated factors, and survival impact of ONI in SNSCC.MethodsThe National Cancer Database was queried for patients with SNSCC from 2004 to 2016. Data regarding patient demographics, clinicopathology, and treatment were obtained. Univariate and multivariate logistic regression and Kaplan-Meier analyses were conducted to identify predictors of ONI with odds ratios (ORs) and overall survival.ResultsIn total, 522 patients satisfied inclusion criteria. Most patients were elderly (>60 years old, 55.0%), male (67.2%), White (86.4%), and insured with Medicare (44.1%). Cases of SNSCC most frequently involved the paranasal sinuses (69.7%), were T-stage 4 (50.6%), moderately differentiated (52.5%), underwent treatment at academic centers (76.4%), and lacked lymphovascular invasion (LVI, 84.4%). ONI was observed in 10.9% of patients. Following propensity score matching, ONI significantly negatively impacted survival: 3 year survival was 65% for patients without ONI and 35% for patients with ONI (log-rank P < .001). The highest rate of ONI was observed in patients with LVI (31.4%). On multivariate analysis, LVI was the sole predictor of ONI (OR: 6.75, 95% confidence interval: 3.09-14.73, P < .001).ConclusionsONI was identified in 10.9% of patients with SNSCC and was found to be a negative prognostic factor for survival. Patients with identified LVI may benefit from END.Level of Evidence: 4.