检测肺癌患者血清Cathepsin X及Cystatin C的临床意义

BACKGROUND AND OBJECTIVE: Cathepsin X (Cat X) has been identifed as a member of cathepsin family. Studies have shown that Cat X is involved in tumorigenesis and tumor development of various cancers. The aim of this study is to investigate the relationship between the clinicopathological prognosis and the levels of Cat X and cystatin C in the serum of patients with lung cancer. METHODS: Blood samples were collected from 84 patients with lung cancer and 36 healthy control subjects. Cat X and cystatin C were determined by quantitative ELISA. RESULTS: Cat X and cystatin C levels were signifcantly higher in the patients with lung cancer than that in the healthy control subjects (P < 0.01). Cat X level was correlated with the pathological types of lung cancer (P=0.076). Cystatin C was positively correlated with TNM stage (P=0.01). Furthermore, cystatin C/Cat X was correlated with lymph node metastasis (P=0.058). The patients with high Cat X levels experienced signifcantly shorter overall survival rates compared with those with low Cat X. Univariate analysis indicated that Cat X and TNM stage were related to overall survival. Multivariate Cox analysis indicated that TNM stage may be used as an independent prognostic variable in patients with lung cancer. CONCLUSION: Cat X and cystatin C levels were signifcantly higher in patients with lung cancer. Cat X and cystatin C detection in the sera may contribute to the diagnosis of lung cancer and may be used to evaluate the prognosis of patients with NSCLC.