Tophinin-associated protein expression is an independent prognostic biomarker in lung adenocarcinoma

Background: Lung cancer is the leading cause of cancer-related deaths worldwide, with lung adenocarcinoma (LAC) representing the most common subtype. Trophinin-associated protein (TROAP) is a cytoplasmic protein first identified to mediate the process of embryo transplantation, which has been recently found to be involved in microtubule regulation. However, limited information about the role of TROAP in LAC is available. Methods: We evaluated the relationship of TROAP expression in LAC tissues with clinical pathologic parameters and the survival time in LAC patients based on a statistical analysis of The Cancer Genome Atlas (TCGA) lung cancer data (N=528). Differences in survival between high and low expression groups (median expression cutoff) from the Cox univariate/multivariate regression analysis were then compared. Results: According to the Chi-square tests, we found high TROAP expression correlated with younger age (5_60) (P=0.047), male sex (P<0.005), an earlier T-stage (P=0.011), N-stage (P=0.017), M-stage (P=0.022), TNM (P=0.007), and a longer smoking history (>30 pack-year) (P<0.001). A Kaplan-Meier analysis demonstrated that high TROAP expression may correspond with poor overall survival of LAC patients in T3 stage (P=0.0013), N0 stage (P=0.014), and M0 stage (P=0.0023). Multivariate analysis confirmed that TROAP expression was related to overall survival in LAC patients independently [hazard ratio (FIR): 1.784, 95% confidence interval (CI): 1.072-2.968, P=0.026]. Conclusions: Our results suggested that TROAP is an independent prognostic biomarker of poor survival in LAC.