Expression and clinicopathological implication of DcR3 in lung cancer tissues: a tissue microarray study with 365 cases

Background: Decoy receptor 3 (DcR3) has been reported to be involved in different cancers. However, few related researches have been accomplished on the role of DcR3 in lung cancer. Objective: To explore the expression level and clinicopathological implication of DcR3 protein in lung cancer tissues. Materials and methods: Immunohistochemistry was used to examine DcR3 protein expression in lung cancer (n=365) and normal lung tissues (n=26). The relationships between DcR3 expression and clinical parameters were further investigated. Furthermore, the diagnostic and clinicopathological value of DcR3 mRNA was analyzed based on The Cancer Genome Atlas database in lung cancer patients. Results: Compared to normal lung tissues, DcR3 expression was significantly higher in lung cancer (P=0.007) tissues, including small-cell lung cancer (P=0.001) and non-small-cell lung cancer (P=0.008). In addition, DcR3 expression was related to tumor-node-metastasis (TNM) stage (P<0.001), tumor diameter (P=0.007), distant metastasis (P<0.001), and lymph node metastasis (P<0.001) in lung cancers. When concerning non-small-cell lung cancer, consistent correlations between DcR3 expression and TNM stage (P<0.001), tumor diameter (P=0.019), distant metastasis (P<0.001), and lymph node metastasis (P<0.001) were found. Simultaneously, in small-cell lung cancer, TNM stage (P=0.004) and lymph node metastasis (P=0.005) were also associated with DcR3 expression. Additionally, receiver operator characteristic curve revealed that the area under curve (AUC) of DcR3 was 0.637 (95% confidence interval [CI] 0.531-0.742) for lung cancer. Furthermore, DcR3 was overexpressed in both adenocarcinoma and squamous cell carcinoma tissues than in noncancerous lung tissues (all P<0.0001) based on the data from The Cancer Genome Atlas. AUC of DcR3 was 0.726 (95% CI 0.644-0.788) for lung adenocarcinoma patients and 0.647 (95% CI 0.566-0.728) for squamous cell carcinoma patients. DcR3 expression was also related to the overall survival (P<0.001) and disease-free survival (P<0.001) of lung adenocarcinoma according to the data from The Cancer Genome Atlas. Conclusion: Our study confirms that DcR3 might be involved in the tumorigenesis and deterioration of lung cancer. Therefore, the detection of DcR3 gains the potential to be applied in the clinic for screening and progression prediction of lung cancer.