Association between Carbonic anhydrase 9 expression and poor prognosis in sinonasal squamous cell carcinoma

Abstract Background: Carbonic anhydrase 9(CA9), as a member of the carbonic anhydrase enzyme family, was an endogenous marker of hypoxia. Previous studies suggested CA9 expression was correlated with poor prognosis in multiple types of malignancies. The purpose of current study was to evaluate the role of CA9 as a prognostic marker in sinonasal squamous cell carcinoma(SNSCC).Patients and methods: We assessed the immunohistochemical expression of CA9 in 63 tumor specimens of patients who underwent curative surgery and evaluated the relationship between the expression levels and clinicopathological factors as well as outcome.Results: We observed positive expression of CA9 in 21(33.3%) patients. Positive expression of CA9 in patients with SNSCC was significantly correlated with local recurrence (p=0.016) and both overall survival (OS) (p=0.003) and disease-free survival (DFS) (p=0.002). In Cox's multivariate analysis, CA9 expression was an independent negative prognostic factor for OS (p=0.027) and DFS (p=0.018).Conclusions: Our findings demonstrated that CA9 overexpression could be used as an independent prognostic biomarker and therapeutic target in SNSCC.