ObjectiveTo investigate the expression of squamous cell carcinoma antigen (SCCA) in patients of chronic rhinosinusitis with nasal polyps (CRSwNP) and its application value in different subtypes of nasal polyps.MethodsA total of 74 patients with CRSwNP and 40 healthy volunteers were selected as the research objects. CRSwNP patients were divided into non-eosinophilic CRSwNP group (non-ECRSWNP, n=33) and eosinophilic CRSwNP group (eCRSwNP, n=41) according to the eosinophilic infiltration in postoperative histopathological sections. The peripheral blood of the enrolled patients was collected before surgery to detect the serum concentration of SCCA, and to observe the correlation between SCCA and clinical indicators, which was analyzed for the difference of SCCA concentration between patients with different endotype.ResultsCompared with the control group, the serum SCCA expression level in CRSwNP group was significantly increased (P < 0.000 1). Compared with the non-eCRSwNP group, the serum SCCA expression level was significantly increased in the eCRSwNP group (P < 0.000 1). Serum SCCA concentration in CRSwNP patients was positively correlated with eosinophil count in peripheral blood (r=0.404, P=0.000 4) and tissue eosinophil ratio (r=0.283, P=0.015). Binary logistic regression and ROC analysis indicated that the serum SCCA level was significantly correlated with CRSwNP tissue endotype (AUC=0.844, P=0.000).ConclusionSerum SCCA expression in CRSwNP patients is up-regulated and associated with tissue eosinophilic inflammation. The expression level of SCCA may be helpful for the preoperative identification of CRSwNP endotype.