Clinical Diagnosis and Treatment Analyses on SMARCB1 (Integrase Interactor 1)-Deficient Sinonasal Carcinoma: Case Series with Systematic Review of the Literature.

OBJECTIVE:This study aims to improve the understanding of SMARCB1 (integrase interactor 1)-deficient sinonasal carcinoma (SDSC) by analyzing its clinical features, treatment strategies, and prognosis. METHODS:Sixty-nine patients were included in this research: 15 new cases from Beijing Tongren Hospital and 54 previously reported cases. We analyzed and summarized patients' epidemiologic data, clinical features, and treatment regimens. Main outcomes were overall survival (OS) and recurrence-free survival (RFS). Univariate and multivariate analyses were performed using a Cox regression model for OS and RFS. RESULTS:SDSC was more common in men than women with a median age of 52 years (range, 21-89 years). Epistaxis (40.0%) and headache (36.7%) were the major symptoms. The most common affected paranasal sinus was the ethmoid sinus (58.0%). For TNM stage, 66.7% cases were first diagnosed as T4N0M0. The tumor cells were complete loss of integrase interactor 1 in all cases by immunohistochemical analysis. However, 72.5% patients were first misdiagnosed initially. The 1-year, 3-year, and 5-year OS and RFS were 85.3%, 51.8%, 47.8%; and 56.8%, 38.2%, and 35.3%, respectively. The RFS of comprehensive treatment based on surgery was better than that of systemic therapy without surgery (P < 0.05). In addition, the OS and RFS of surgery with chemoradiotherapy was better than that of surgery with radiotherapy (P < 0.05). Univariate and multivariate analysis identified treatment modality as an independent prognostic factor for patients with SDSC. CONCLUSIONS:Immunohistochemical analysis of SDSC during initial biopsy can prevent delays in diagnosis and treatment. Radical surgery resection combined with chemoradiotherapy may be the preferred treatment modality.