Abstract: Abstract：Objective To investigate the expression of MUC1 protein in serum and cancer tissues in patients with different types of non-small cell lung cancer (NSCLC), and to analyze its predictive value in early clinical diagnosis and treatment of NSCLC patients. Methods From December 2017 to December 2018, samples of peripheral blood and lung tissues of 34 cases of lung squamous cell carcinoma, 65 cases of lung adenocarcinoma and 20 cases of non-lung cancer were collected from the General Hospital of Ningxia Medical University. The serum expression of MUC1 protein was detected by enzyme-linked immunosorbent assay (ELISA). After HE staining confirmed that the lung tissue specimens met the pathological requirements, MUC1 protein expression was detected by immunohistochemical staining. The clinical value of serum MUC1 protein for predicting different types of NSCLC patients was performed by ROC curve analysis. Results The expressions of MUC1 protein in serum and cancer tissues were significantly higher in lung squamous cell carcinoma group and lung adenocarcinoma group than those of non-lung cancer group (P＜0.05). The optimum critical value of serum MUC1 protein in the diagnosis of lung squamous cell carcinoma was 33.23 U/mL, with a sensitivity of 52.94% and a specificity of 100%. The positive expression rates of MUC1 proteins in serum and cancer tissues of patients with lung squamous cell carcinoma were not related to the differences of pathological differentiation, TNM stage, age and sex (P＞0.05). The optimal critical value of serum MUC1 protein in the diagnosis of lung adenocarcinoma was 31.31 U/mL, with a sensitivity of 61.54% and a specificity of 95%. The positive expression rates of MUC1 proteins in serum and cancer tissues were significantly higher in lung adenocarcinoma patients with middle-low tissue differentiation and TNM stage Ⅲ-Ⅳ than those of patients with high tissue differentiation and TNM stage Ⅰ-Ⅱ(P＜0.05). Conclusion MUC1 protein is highly expressed in NSCLC patients, which may be of predictive significance for early diagnosis and treatment of lung adenocarcinoma, and has no obvious prognostic significance for lung squamous cell carcinoma.

Key words: mucin-1, carcinoma, non-small-cell lung, early diagnosis, ROC curve, immunohistochemistry