Impact of Clinical Factors and Treatments on SMARCB1 (INI‐1)‐Deficient Sinonasal Carcinoma

Abstract The objective of this study was to report outcomes for 19 consecutive patients with SMARCB1 (INI‐1)‐deficient sinonasal carcinoma. Patients were treated from 2014 to 2021 and followed for a median of 22.3 months. The median overall survival (OS) and disease‐free survival (DFS) were 31.8 and 9.9 months, respectively. Patients with nasal cavity or maxillary sinus tumors had 84% better disease‐specific survival (DSS) (hazard ratio [HR], 0.136; 95% confidence interval [CI], 0.028‐0.66; p = .005) and 71% better DFS (HR, 0.29; 95% CI, 0.097‐0.84; p = .041) than patients with other sinonasal sites. Patients who received induction chemotherapy were 76% less likely to die of disease (DSS HR, 0.241; 95% CI, 0.058‐1.00; p = .047). In the largest single‐institution study of SMARCB1‐deficient sinonasal carcinoma to date, OS and DFS approached 3 years and 1 year, respectively, but were better for nasal cavity and maxillary sinus tumors. Patients may benefit from induction chemotherapy.