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

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. Therefore, this study was to evaluate the role of CA9 in sinonasal squamous cell carcinoma (SNSCC) and to determine whether this biomarker was associated with patient clinicopathologic characteristics and prognosis. We assessed 63 patients diagnosed with SNSCC in 2013–2017 who underwent curative surgery. Tumor specimens was immunohistochemically analyzed for CA9 expression. The expression levels of CA9 was evaluated in relation to clinicopathological factors and prognosis. Positive expression of CA9 was observed in 21 (33.3%) patients and was significantly correlated with local recurrence (p = 0.016), 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 = 0.048) and DFS (p = 0.019). Our findings demonstrated that CA9 overexpression could be used as an independent prognostic biomarker and therapeutic target in SNSCC. • This is the first study demonstrating CA9 expression in 63 patients diagnosed with SNSCC in 2013-2017. • CA9 is an independent prognostic marker for SNSCC patients who have undergone surgical treatment. • CA9 may serve as a novel therapeutic target for SNSCC. [ABSTRACT FROM AUTHOR]